def extract_tree_block(self):
lines = iter(self.data)<EOL>while <NUM_LIT:1>:<EOL><INDENT>try:<EOL><INDENT>line = next(lines).strip()<EOL><DEDENT>except StopIteration:<EOL><INDENT>break<EOL><DEDENT>if line.lower() == "<STR_LIT>":<EOL><INDENT>while <NUM_LIT:1>:<EOL><INDENT>sub = next(lines).strip().split()<EOL>if not sub:<EOL><INDENT>continue<EOL><DEDENT>if sub[<NUM_LIT:0>].lower() == "<STR_LIT>":<EOL><INDENT>while sub[<NUM_LIT:0>] != "<STR_LIT:;>":<EOL><INDENT>sub = next(lines).strip().split()<EOL>self.tdict[sub[<NUM_LIT:0>]] = sub[-<NUM_LIT:1>].strip("<STR_LIT:U+002C>")<EOL><DEDENT><DEDENT>if sub[<NUM_LIT:0>].lower().startswith("<STR_LIT>"):<EOL><INDENT>self.newicks.append(sub[-<NUM_LIT:1>])<EOL><DEDENT>if sub[<NUM_LIT:0>].lower() == "<STR_LIT>":<EOL><INDENT>break<EOL><DEDENT><DEDENT><DEDENT><DEDENT>
iterate through data file to extract trees