Error in ok handler

[dinfyru]

I have error when try to use ok handler. redux-api-middleware - 3.0.1

      ok: async res => {
        const json = await res.json();
        return res.ok && !json.error;
      },

Error

payload: 
message: "Failed to execute 'json' on 'Response': body stream is locked"
name: "InternalError"

[iamandrewluca]

@dinfyru try this one

ok: async res => {
                     /* vvvvvvvv */
  const json = await res.clone().json();
  return res.ok && !json.error;
},

Related #218