NoMethodError: undefined method `first' for nil:NilClass

[viniciusmo]

My code

audio = Speech::AudioToText.new("tmp/sounds/teste.wav")
p audio.to_json

And the tests are failure

4 tests, 0 assertions, 0 failures, 3 errors

[viniciusmo]

1. Error:
   test_audio_splitter(SpeechAudioSplitterTest):
   NoMethodError: undefined method first' for nil:NilClass /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_inspector.rb:55:ininitialize'
   /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_splitter.rb:76:in new' /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_splitter.rb:76:ininitialize'
   /Users/viniciusmo/Open Source/speech2text/test/audio_splitter_test.rb:9:in new' /Users/viniciusmo/Open Source/speech2text/test/audio_splitter_test.rb:9:intest_audio_splitter'

2. Error:
   test_audio_to_text(SpeechAudioToTextTest):
   NoMethodError: undefined method first' for nil:NilClass /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_inspector.rb:55:ininitialize'
   /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_splitter.rb:76:in new' /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_splitter.rb:76:ininitialize'
   /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_to_text.rb:31:in new' /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_to_text.rb:31:into_json'
   /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_to_text.rb:20:in to_text' /Users/viniciusmo/Open Source/speech2text/test/audio_to_text_test.rb:13:intest_audio_to_text'

3. Error:
   test_longer_audio(SpeechAudioToTextTest):
   NoMethodError: undefined method first' for nil:NilClass /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_inspector.rb:55:ininitialize'
   /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_splitter.rb:76:in new' /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_splitter.rb:76:ininitialize'
   /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_to_text.rb:31:in new' /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_to_text.rb:31:into_json'
   /Users/viniciusmo/Open Source/speech2text/lib/speech/audio_to_text.rb:20:in to_text' /Users/viniciusmo/Open Source/speech2text/test/audio_to_text_test.rb:18:intest_longer_audio'

4 tests, 0 assertions, 0 failures, 3 errors