def line_chunker(text, getreffs, lines=<NUM_LIT:30>):
level = len(text.citation)<EOL>source_reffs = [reff.split("<STR_LIT::>")[-<NUM_LIT:1>] for reff in getreffs(level=level)]<EOL>reffs = []<EOL>i = <NUM_LIT:0><EOL>while i + lines - <NUM_LIT:1> < len(source_reffs):<EOL><INDENT>reffs.append(tuple([source_reffs[i]+"<STR_LIT:->"+source_reffs[i+lines-<NUM_LIT:1>], source_reffs[i]]))<EOL>i += lines<EOL><DEDENT>if i < len(source_reffs):<EOL><INDENT>reffs.append(tuple([source_reffs[i]+"<STR_LIT:->"+source_reffs[len(source_reffs)-<NUM_LIT:1>], source_reffs[i]]))<EOL><DEDENT>return reffs<EOL>
Groups line reference together

    :param text: Text object
    :type text: MyCapytains.resources.text.api
    :param getreffs: Callback function to retrieve text
    :type getreffs: function(level)
    :param lines: Number of lines to use by group
    :type lines: int
    :return: List of grouped urn references with their human readable version
    :rtype: [(str, str)]