def alpha_cased(text, lower=False):
text = "<STR_LIT>".join(filter(<EOL>lambda c: c.isalpha() or c == GENERIC_PROTOCOL_KEY, text))<EOL>return text.lower() if lower else text.upper()<EOL>
Filter text to just letters and homogenize case.

:param str text: what to filter and homogenize.
:param bool lower: whether to convert to lowercase; default uppercase.
:return str: input filtered to just letters, with homogenized case.