add doc, remove further println

opentelemetry-otlp/examples/basic-otlp-http/src/main.rs

@@ -1,3 +1,4 @@
+/// To use hyper as the HTTP client - cargo run --features="hyper" --no-default-features
 use once_cell::sync::Lazy;
 use opentelemetry::{
     global,

opentelemetry-otlp/src/exporter/http/mod.rs

@@ -165,13 +165,11 @@ impl HttpExporterBuilder {
             },
             None => self.exporter_config.timeout,
         };
-        println!("build_client: timeout={:?}", timeout);
         let http_client = self
             .http_config
             .client
             .take()
             .ok_or(crate::Error::NoHttpClient)?;
-        println!("build_client: http_client={:?}", http_client);
         #[allow(clippy::mutable_key_type)] // http headers are not mutated
         let mut headers: HashMap<HeaderName, HeaderValue> = self
             .http_config

opentelemetry-otlp/src/exporter/mod.rs

@@ -204,7 +204,6 @@ impl<B: HasExportConfig> WithExportConfig for B {
     }
 
     fn with_protocol(mut self, protocol: Protocol) -> Self {
-        println!("WithExportConfig::with_protocol");
         self.export_config().protocol = protocol;
         self
     }

opentelemetry-otlp/src/span.rs

@@ -54,7 +54,6 @@ impl SpanExporterBuilder<NoExporterBuilderSet> {
 
     #[cfg(any(feature = "http-proto", feature = "http-json"))]
     pub fn with_http(self) -> SpanExporterBuilder<HttpExporterBuilderSet> {
-        println!("SpanExporterBuilder::with_http");
         SpanExporterBuilder {
             client: HttpExporterBuilderSet(HttpExporterBuilder::default()),
         }