def first_lines(self, lines, *ignores):
ignore = set()<EOL>for ign in ignores:<EOL><INDENT>ignore.update(ign)<EOL><DEDENT>lset = set()<EOL>for l in lines:<EOL><INDENT>if l in ignore:<EOL><INDENT>continue<EOL><DEDENT>new_l = self.first_line(l)<EOL>if new_l not in ignore:<EOL><INDENT>lset.add(new_l)<EOL><DEDENT><DEDENT>return lset<EOL>
Map the line numbers in `lines` to the correct first line of the
        statement.

        Skip any line mentioned in any of the sequences in `ignores`.

        Returns a set of the first lines.