fix: Explicit return types & internal constructors

src/main/kotlin/com/vonage/client/kt/Conversion.kt

@@ -19,16 +19,17 @@ import com.vonage.client.conversion.*
 import java.time.Instant
 import java.util.*
 
-class Conversion(private val conversionClient: ConversionClient) {
+class Conversion internal constructor(private val conversionClient: ConversionClient) {
 
-    private fun convert(type: ConversionRequest.Type, messageId: String, delivered: Boolean, timestamp: Instant?) =
+    private fun convert(type: ConversionRequest.Type,
+                        messageId: String, delivered: Boolean, timestamp: Instant?): Unit =
         conversionClient.submitConversion(type, messageId, delivered,
             if (timestamp != null) Date.from(timestamp) else null
         )
 
-    fun convertSms(messageId: String, delivered: Boolean, timestamp: Instant? = null) =
+    fun convertSms(messageId: String, delivered: Boolean, timestamp: Instant? = null): Unit =
         convert(ConversionRequest.Type.SMS, messageId, delivered, timestamp)
 
-    fun convertVoice(callId: String, delivered: Boolean, timestamp: Instant? = null) =
+    fun convertVoice(callId: String, delivered: Boolean, timestamp: Instant? = null): Unit =
         convert(ConversionRequest.Type.VOICE, callId, delivered, timestamp)
 }

src/main/kotlin/com/vonage/client/kt/Messages.kt

@@ -23,7 +23,7 @@ import com.vonage.client.messages.messenger.*
 import com.vonage.client.messages.viber.*
 import java.util.UUID
 
-class Messages(private val messagesClient: MessagesClient) {
+class Messages internal constructor(private val messagesClient: MessagesClient) {
     fun send(message: MessageRequest, sandbox: Boolean = false): UUID =
         (if (sandbox) messagesClient.useSandboxEndpoint()
             else messagesClient.useRegularEndpoint()).sendMessage(message).messageUuid

src/main/kotlin/com/vonage/client/kt/NumberInsight.kt

@@ -17,7 +17,7 @@ package com.vonage.client.kt
 
 import com.vonage.client.insight.*
 
-class NumberInsight(private val niClient: InsightClient) {
+class NumberInsight internal constructor(private val niClient: InsightClient) {
 
     fun basic(number: String, countryCode: String? = null): BasicInsightResponse =
         niClient.getBasicNumberInsight(number, countryCode)

src/main/kotlin/com/vonage/client/kt/NumberVerification.kt

@@ -18,7 +18,7 @@ package com.vonage.client.kt
 import com.vonage.client.camara.numberverification.*
 import java.net.URI
 
-class NumberVerification(private val nvClient: NumberVerificationClient) {
+class NumberVerification internal constructor(private val nvClient: NumberVerificationClient) {
     private var redirectUri: URI? = null
 
     fun createVerificationUrl(phoneNumber: String, redirectUrl: String, state: String? = null): URI {

src/main/kotlin/com/vonage/client/kt/Numbers.kt

@@ -17,25 +17,25 @@ package com.vonage.client.kt
 
 import com.vonage.client.numbers.*
 
-class Numbers(private val numbersClient: NumbersClient) {
+class Numbers internal constructor(private val numbersClient: NumbersClient) {
 
     fun number(countryCode: String, msisdn: String) = ExistingNumber(countryCode, msisdn)
 
     inner class ExistingNumber internal constructor(val countryCode: String, val msisdn: String) {
 
-        fun buy(targetApiKey: String? = null) =
+        fun buy(targetApiKey: String? = null): Unit =
             numbersClient.buyNumber(countryCode, msisdn, targetApiKey)
 
-        fun cancel(targetApiKey: String? = null) =
+        fun cancel(targetApiKey: String? = null): Unit =
             numbersClient.cancelNumber(countryCode, msisdn, targetApiKey)
 
-        fun update(properties: UpdateNumberRequest.Builder.() -> Unit) =
+        fun update(properties: UpdateNumberRequest.Builder.() -> Unit): Unit =
             numbersClient.updateNumber(UpdateNumberRequest.builder(msisdn, countryCode).apply(properties).build())
     }
 
-    fun listOwned(filter: ListNumbersFilter.Builder.() -> Unit = {}) =
+    fun listOwned(filter: ListNumbersFilter.Builder.() -> Unit = {}): ListNumbersResponse =
         numbersClient.listNumbers(ListNumbersFilter.builder().apply(filter).build())
 
-    fun searchAvailable(filter: SearchNumbersFilter.Builder.() -> Unit) =
+    fun searchAvailable(filter: SearchNumbersFilter.Builder.() -> Unit): SearchNumbersResponse =
         numbersClient.searchNumbers(SearchNumbersFilter.builder().apply(filter).build())
 }

src/main/kotlin/com/vonage/client/kt/Redact.kt

@@ -17,20 +17,20 @@ package com.vonage.client.kt
 
 import com.vonage.client.redact.*
 
-class Redact(private val redactClient: RedactClient) {
+class Redact internal constructor(private val redactClient: RedactClient) {
 
-    fun redactSms(messageId: String, direction: RedactRequest.Type = RedactRequest.Type.OUTBOUND) =
+    fun redactSms(messageId: String, direction: RedactRequest.Type = RedactRequest.Type.OUTBOUND): Unit =
         redactClient.redactTransaction(messageId, RedactRequest.Product.SMS, direction)
 
-    fun redactMessage(messageId: String, direction: RedactRequest.Type = RedactRequest.Type.OUTBOUND) =
+    fun redactMessage(messageId: String, direction: RedactRequest.Type = RedactRequest.Type.OUTBOUND): Unit =
         redactClient.redactTransaction(messageId, RedactRequest.Product.MESSAGES, direction)
 
-    fun redactCall(callId: String, direction: RedactRequest.Type = RedactRequest.Type.OUTBOUND) =
+    fun redactCall(callId: String, direction: RedactRequest.Type = RedactRequest.Type.OUTBOUND): Unit =
         redactClient.redactTransaction(callId, RedactRequest.Product.VOICE, direction)
 
-    fun redactInsight(requestId: String) =
+    fun redactInsight(requestId: String): Unit =
         redactClient.redactTransaction(requestId, RedactRequest.Product.NUMBER_INSIGHTS)
 
-    fun redactVerification(requestId: String) =
+    fun redactVerification(requestId: String): Unit =
         redactClient.redactTransaction(requestId, RedactRequest.Product.VERIFY)
 }

src/main/kotlin/com/vonage/client/kt/SimSwap.kt

@@ -16,12 +16,13 @@
 package com.vonage.client.kt
 
 import com.vonage.client.camara.simswap.*
+import java.time.Instant
 
-class SimSwap(private val simSwapClient: SimSwapClient) {
+class SimSwap internal constructor(private val simSwapClient: SimSwapClient) {
 
     fun checkSimSwap(phoneNumber: String, maxAgeHours: Int = 240): Boolean =
         simSwapClient.checkSimSwap(phoneNumber, maxAgeHours)
 
-    fun retrieveSimSwapDate(phoneNumber: String) =
+    fun retrieveSimSwapDate(phoneNumber: String): Instant? =
         simSwapClient.retrieveSimSwapDate(phoneNumber)
 }

src/main/kotlin/com/vonage/client/kt/Sms.kt

@@ -18,7 +18,7 @@ package com.vonage.client.kt
 import com.vonage.client.sms.*
 import com.vonage.client.sms.messages.*
 
-class Sms(private val smsClient: SmsClient) {
+class Sms internal constructor(private val smsClient: SmsClient) {
 
     private fun send(msgObj: Message, statusReport: Boolean?, ttl: Int?,
                      messageClass: Message.MessageClass?, clientRef: String?,

src/main/kotlin/com/vonage/client/kt/Verify.kt

@@ -27,18 +27,18 @@ class Verify(private val verify2Client: Verify2Client) {
         VerificationRequest.builder().brand(brand).apply(init).build()
     )
 
-    fun cancelVerification(requestId: UUID) = verify2Client.cancelVerification(requestId)
+    fun cancelVerification(requestId: UUID): Unit = verify2Client.cancelVerification(requestId)
 
-    fun cancelVerification(requestId: String) = cancelVerification(UUID.fromString(requestId))
+    fun cancelVerification(requestId: String): Unit = cancelVerification(UUID.fromString(requestId))
 
-    fun nextWorkflow(requestId: UUID) = verify2Client.nextWorkflow(requestId)
+    fun nextWorkflow(requestId: UUID): Unit = verify2Client.nextWorkflow(requestId)
 
-    fun nextWorkflow(requestId: String) = nextWorkflow(UUID.fromString(requestId))
+    fun nextWorkflow(requestId: String): Unit = nextWorkflow(UUID.fromString(requestId))
 
-    fun checkVerificationCode(requestId: UUID, code: String) =
+    fun checkVerificationCode(requestId: UUID, code: String): VerifyCodeResponse =
         verify2Client.checkVerificationCode(requestId, code)
 
-    fun checkVerificationCode(requestId: String, code: String) =
+    fun checkVerificationCode(requestId: String, code: String): VerifyCodeResponse =
         checkVerificationCode(UUID.fromString(requestId), code)
 
     fun isValidVerificationCode(requestId: String, code: String): Boolean =

src/main/kotlin/com/vonage/client/kt/VerifyLegacy.kt

@@ -17,7 +17,7 @@ package com.vonage.client.kt
 
 import com.vonage.client.verify.*
 
-class VerifyLegacy(private val verifyClient: VerifyClient) {
+class VerifyLegacy internal constructor(private val verifyClient: VerifyClient) {
 
     fun verify(number: String, brand: String, properties: (VerifyRequest.Builder.() -> Unit) = {}): VerifyResponse =
         verifyClient.verify(VerifyRequest.builder(number, brand).apply(properties).build())

src/main/kotlin/com/vonage/client/kt/Voice.kt

@@ -29,21 +29,21 @@ class Voice(private val voiceClient: VoiceClient) {
 
         fun info(): CallInfo = voiceClient.getCallDetails(callId)
 
-        fun hangup() = voiceClient.terminateCall(callId)
+        fun hangup(): Unit = voiceClient.terminateCall(callId)
 
-        fun mute() = voiceClient.muteCall(callId)
+        fun mute(): Unit = voiceClient.muteCall(callId)
 
-        fun unmute() = voiceClient.unmuteCall(callId)
+        fun unmute(): Unit = voiceClient.unmuteCall(callId)
 
-        fun earmuff() = voiceClient.earmuffCall(callId)
+        fun earmuff(): Unit = voiceClient.earmuffCall(callId)
 
-        fun unearmuff() = voiceClient.unearmuffCall(callId)
+        fun unearmuff(): Unit = voiceClient.unearmuffCall(callId)
 
-        fun transfer(vararg actions: Action) = voiceClient.transferCall(callId, Ncco(actions.asList()))
+        fun transfer(vararg actions: Action): Unit = voiceClient.transferCall(callId, Ncco(actions.asList()))
 
-        fun transfer(nccoUrl: String) = voiceClient.transferCall(callId, nccoUrl)
+        fun transfer(nccoUrl: String): Unit = voiceClient.transferCall(callId, nccoUrl)
 
-        fun transfer(nccoUrl: URI) = transfer(nccoUrl.toString())
+        fun transfer(nccoUrl: URI): Unit = transfer(nccoUrl.toString())
 
         fun sendDtmf(digits: String): DtmfResponse = voiceClient.sendDtmf(callId, digits)
 

src/test/kotlin/com/vonage/client/kt/VerifyLegacyTest.kt

@@ -163,6 +163,8 @@ class VerifyLegacyTest : AbstractTest() {
     fun `existing request hashCode is based on the requestId`() {
         assertEquals(requestId.hashCode(), existingRequest.hashCode())
         assertEquals(existingRequest, verifyClient.request(requestId))
+        assertEquals(existingRequest, existingRequest)
+        assertFalse(existingRequest.equals(requestId))
     }
 
     @Test