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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def fixup_building_sdist():
    ''' Check for 'sdist' and ensure we always build BokehJS when packaging

    Source distributions do not ship with BokehJS source code, but must ship
    with a pre-built BokehJS library. This function modifies ``sys.argv`` as
    necessary so that ``--build-js`` IS present, and ``--install-js` is NOT.

    Returns:
        None

    '''
    if "sdist" in sys.argv:
        if "--install-js" in sys.argv:
            print("Removing '--install-js' incompatible with 'sdist'")
            sys.argv.remove('--install-js')
        if "--build-js" not in sys.argv:
            print("Adding '--build-js' required for 'sdist'")
            sys.argv.append('--build-js')