question: @ Override public String toString ( ) { StringBuffer text = new StringBuffer ( ) ; if ( m_trainInstances == null ) { text . append ( "\tGain Ratio evaluator has not been built" ) ; } else { text . append ( "\tGain Ratio feature evaluator" ) ; if ( ! m_missing_merge ) { text . append ( "\n\tMissing values treated as seperate" ) ; } } text . append ( "\n" ) ; return text . toString ( ) ; }
target:  Return a description of the evaluator