def __trim_extension_dot(ext):
if ext is None:<EOL><INDENT>return None<EOL><DEDENT>if ext == "<STR_LIT>":<EOL><INDENT>return "<STR_LIT>"<EOL><DEDENT>while ext[<NUM_LIT:0>] == "<STR_LIT:.>":<EOL><INDENT>ext = ext[<NUM_LIT:1>:]<EOL><DEDENT>return ext<EOL>
trim leading dots from extension.