Add missing 2 blank lines after end of function or class.

def fix_e305(self, result):
        """Add missing 2 blank lines after end of function or class."""
        add_delete_linenum = 2 - int(result['info'].split()[-1])
        cnt = 0
        offset = result['line'] - 2
        modified_lines = []
        if add_delete_linenum < 0:
            # delete cr
            add_delete_linenum = abs(add_delete_linenum)
            while cnt < add_delete_linenum and offset >= 0:
                if not self.source[offset].strip():
                    self.source[offset] = ''
                    modified_lines.append(1 + offset)  # Line indexed at 1
                    cnt += 1
                offset -= 1
        else:
            # add cr
            cr = '\n'
            # check comment line
            while True:
                if offset < 0:
                    break
                line = self.source[offset].lstrip()
                if not line:
                    break
                if line[0] != '#':
                    break
                offset -= 1
            offset += 1
            self.source[offset] = cr + self.source[offset]
            modified_lines.append(1 + offset)   # Line indexed at 1.
        return modified_lines