#NEWLINE# def add_gc_metadata( self , feature_name , feature_data ) : #NEWLINE# #INDENT# if ( feature_name in self . _positional_metadata ) : #NEWLINE# #INDENT# _raise_duplicate_error ( ( 'Found duplicate GC label %r.' % feature_name ) ) #NEWLINE# #UNINDENT# self . _positional_metadata [ feature_name ] = feature_data