def process_header(self, header):
metadata = {}<EOL>for line in header.split("<STR_LIT:\n>"):<EOL><INDENT>line = line.strip()<EOL>for tag in self.header_tags:<EOL><INDENT>tag_text = "<STR_LIT>".format(tag)<EOL>if line.lower().startswith(tag_text):<EOL><INDENT>metadata[tag] = line[len(tag_text) + <NUM_LIT:1> :].strip()<EOL><DEDENT><DEDENT><DEDENT>return metadata<EOL>
Parse the header for additional metadata.

Parameters
----------
header : str
    All the lines in the header.

Returns
-------
dict
    The metadata in the header.