question: protected double compute ( String value ) { if ( value != null ) { try { return Double . parseDouble ( value ) ; } catch ( NumberFormatException e ) { if ( POSITIVE_INFINITY_STRING . equals ( value ) ) { return Double . POSITIVE_INFINITY ; } else if ( NEGATIVE_INFINITY_STRING . equals ( value ) ) { return Double . NEGATIVE_INFINITY ; } return Double . NaN ; } } return Double . NaN ; }
target:  Computes the result for one input String value.