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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 _clear_context(bin_env=None):
    '''
    Remove the cached pip version
    '''
    contextkey = 'pip.version'
    if bin_env is not None:
        contextkey = '{0}.{1}'.format(contextkey, bin_env)
    __context__.pop(contextkey, None)