question: private void mapPut ( Map map , String name , Object preference ) throws IOException { isEmpty = false ; if ( ( name . length ( ) == 0 ) || ( name == null ) ) { throw new IOException ( "no name specified in preference" + " expression" ) ; } if ( map . put ( name , preference ) != null ) { throw new IOException ( "duplicate map entry: " + name ) ; } }
target:  Insert a preference expression and value into a given map.