fix(TA): fix for tone when given model (#513)

Author: ehdsouza

examples/tone_analyzer_v3.py

@@ -2,6 +2,7 @@
 import json
 from os.path import join, dirname
 from watson_developer_cloud import ToneAnalyzerV3
+from watson_developer_cloud.tone_analyzer_v3 import ToneInput
 
 tone_analyzer = ToneAnalyzerV3(
     username='YOUR SERVICE USERNAME',
@@ -55,3 +56,11 @@
 print(tone)
 print(tone.get_headers())
 print(tone.get_result())
+tone_analyzer.set_detailed_response(False)
+
+print("\ntone() example 7:\n")
+tone_input = ToneInput('I am very happy. It is a good day.')
+tone = tone_analyzer.tone(
+    tone_input=tone_input,
+    content_type="application/json")
+print(json.dumps(tone, indent=2))

watson_developer_cloud/tone_analyzer_v3.py

@@ -170,6 +170,8 @@ def tone(self,
             raise ValueError('tone_input must be provided')
         if content_type is None:
             raise ValueError('content_type must be provided')
+        if isinstance(tone_input, ToneInput):
+            tone_input = self._convert_model(tone_input, ToneInput)
         headers = {
             'Content-Type': content_type,
             'Content-Language': content_language,