def stretch_demo(input_file, output_file, speed):

    # 1. Load the wav file, resample
    print('Loading ', input_file)

    y, sr = librosa.load(input_file)

    # 2. Time-stretch through effects module
    print('Playing back at {:3.0f}% speed'.format(speed * 100))

    y_stretch = librosa.effects.time_stretch(y, speed)

    print('Saving stretched audio to: ', output_file)
    librosa.output.write_wav(output_file, y_stretch, sr)
Add a public ``add_x()`` method to the parent element class.
dataset/ETHPy150Open bmcfee/librosa/examples/time_stretch.py/stretch_demo--crossover with--dataset/ETHPy150Open python-openxml/python-docx/docx/oxml/xmlchemy.py/_BaseChildElement._add_public_adder