Find terms by synonym or alternate label or xref

## Getting a term by its features (e.g. synonyms, xref)

1. Get a term by its name or any of its synonyms.
2. Get a term by one of its xref's.

1. Get a term by its name or any of its synonyms:

       			use OBO::Parser::OBOParser;

       			my $my_parser = OBO::Parser::OBOParser->new();
       			my $ontology = $my_parser->work("my_obo_ontology.obo");

       			my $synonym = "cell-cycle";
       			my $interesting_term = $ontology->get_term_by_name_or_synonym($synonym);

       			print "The name of the term is: ", $interesting_term->name();

2. Get a term by one of its xref's:

       			use OBO::Parser::OBOParser;

       			my $my_parser = OBO::Parser::OBOParser->new();
       			my $ontology = $my_parser->work("my_obo_ontology.obo");

       			my $db  = "Reactome";
       			my $acc = "12345";

       			my $interesting_term = $ontology->get_term_by_xref($db, $acc);

       			print "The name of the term is: ", $interesting_term->name();