def is_shadowed(identifier, ip):
<EOL>return (identifier in ip.user_nsor identifier in ip.user_global_nsor identifier in ip.ns_table['<STR_LIT>'])<EOL>
Is the given identifier defined in one of the namespaces which shadow
    the alias and magic namespaces?  Note that an identifier is different
    than ifun, because it can not contain a '.' character.