haracter set for the input and output data.  This is
                    UTF-8 by default and should not be changed currently as
                    the reporting to Click only works in Python 2 properly.
    :param env: a dictionary with environment variables for overriding.
    :param echo_stdin: if this is set to `True`, then reading from stdin writes
                       to stdout.  This is useful for showing examples in
                       some circumstances.  Note that regular prompts
                       will automatically echo the input.
    :param mix_stderr: if this is set to `False`, then stdout and stderr are
                       preserved as independent streams.  This is useful for
                       Unix-philosophy apps that have predictable stdout and
                       noisy stderr, such that each may be measured
                       independently
    NFTc