question: static String parsePrefix ( String key ) { if ( key == null ) return null ; boolean inquotes = false ; for ( int i = 0 ; i < key . length ( ) ; i ++ ) { char c = key . charAt ( i ) ; if ( c == '"' ) { inquotes = ! inquotes ; } else if ( ( c == '[' || c == '.' ) && ! inquotes ) { return key . substring ( 0 , i ) ; } } return null ; }
target:  Internal method to parse a style prefix.