def _validate_skipfooter_arg(skipfooter):
if not is_integer(skipfooter):<EOL><INDENT>raise ValueError("<STR_LIT>")<EOL><DEDENT>if skipfooter < <NUM_LIT:0>:<EOL><INDENT>raise ValueError("<STR_LIT>")<EOL><DEDENT>return skipfooter<EOL>
Validate the 'skipfooter' parameter.

Checks whether 'skipfooter' is a non-negative integer.
Raises a ValueError if that is not the case.

Parameters
----------
skipfooter : non-negative integer
    The number of rows to skip at the end of the file.

Returns
-------
validated_skipfooter : non-negative integer
    The original input if the validation succeeds.

Raises
------
ValueError : 'skipfooter' was not a non-negative integer.