computes the value of a metric for an operation . concode_field_sep Map<FieldSignature,Set<String>> fields concode_elem_sep Map<String,ClassStats> nestedClasses concode_elem_sep Map<ClassMetricKey,Double> memo concode_elem_sep Map<OperationSignature,Map<String,OperationStats>> operations concode_field_sep void addOperation concode_elem_sep void addField concode_elem_sep ClassStats getNestedClassStats concode_elem_sep boolean hasMatchingSig concode_elem_sep boolean hasMatchingSig