question: public static < T extends GenericEntity > List < T > filterByAnd ( List < T > values , Map < String , ? extends Object > fields ) { if ( values == null ) return null ; List < T > result = null ; if ( UtilValidate . isEmpty ( fields ) ) { result = new LinkedList < T > ( ) ; result . addAll ( values ) ; } else { result = new LinkedList < T > ( ) ; for ( T value : values ) { if ( value . matchesFields ( fields ) ) { result . add ( value ) ; } } } return result ; }
target:  returns the values that match the values in fields