#fixed code
                                private PropertyMapping getPropertyMapping(List<MapperReference> mapperReferences,
                                               List<SourceMethod> methods,
                                               SourceMethod method,
                                               Parameter parameter,
                                               ExecutableElement sourceAccessor,
                                               ExecutableElement targetAcessor,
                                               String dateFormat) {
        Type sourceType = typeFactory.getReturnType( sourceAccessor );
        Type targetType = null;
        String conversionString = parameter.getName() + "." + sourceAccessor.getSimpleName().toString() + "()";
        if ( Executables.isSetterMethod( targetAcessor ) ) {
            targetType = typeFactory.getSingleParameter( targetAcessor ).getType();
        }
        else if ( Executables.isGetterMethod( targetAcessor ) ) {
            targetType = typeFactory.getReturnType( targetAcessor );
        }

        String targetPropertyName = Executables.getPropertyName( targetAcessor );

        String mappedElement = "property '" + Executables.getPropertyName( sourceAccessor ) + "'";

        ParameterAssignment parameterAssignment = mappingResolver.getParameterAssignment(
            method,
            mappedElement,
            mapperReferences,
            methods,
            sourceType,
            targetType,
            targetPropertyName,
            dateFormat,
            conversionString
        );

        PropertyMapping property = new PropertyMapping(
            parameter.getName(),
            Executables.getPropertyName( sourceAccessor ),
            sourceAccessor.getSimpleName().toString(),
            sourceType,
            Executables.getPropertyName( targetAcessor ),
            targetAcessor.getSimpleName().toString(),
            targetType,
            parameterAssignment != null ? parameterAssignment.getMethodReference() : null,
            parameterAssignment != null ? parameterAssignment.getTypeConversion() : null
        );

        if ( !isPropertyMappable( property ) ) {
            messager.printMessage(
                Kind.ERROR,
                String.format(
                    "Can't map property \"%s %s\" to \"%s %s\".",
                    property.getSourceType(),
                    property.getSourceName(),
                    property.getTargetType(),
                    property.getTargetName()
                ),
                method.getExecutable()
            );
        }
        return property;
    }
#vulnerable code 
                                private PropertyMapping getPropertyMapping(List<MapperReference> mapperReferences,
                                               List<SourceMethod> methods,
                                               SourceMethod method,
                                               Parameter parameter,
                                               ExecutableElement sourceAccessor,
                                               ExecutableElement targetAcessor,
                                               String dateFormat) {
        Type sourceType = typeFactory.getReturnType( sourceAccessor );
        Type targetType = null;
        String conversionString = parameter.getName() + "." + sourceAccessor.getSimpleName().toString() + "()";
        if ( Executables.isSetterMethod( targetAcessor ) ) {
            targetType = typeFactory.getSingleParameter( targetAcessor ).getType();
        }
        else if ( Executables.isGetterMethod( targetAcessor ) ) {
            targetType = typeFactory.getReturnType( targetAcessor );
        }

        String targetPropertyName = Executables.getPropertyName( targetAcessor );

        String mappedElement = "property '" + Executables.getPropertyName( sourceAccessor ) + "'";
        MethodReference mappingMethodReference = mappingMethodResolver.getMappingMethodReferenceBasedOnMethod(
            method,
            mappedElement,
            mapperReferences,
            methods,
            sourceType,
            targetType,
            targetPropertyName,
            dateFormat
        );

        TypeConversion conversion = mappingMethodResolver.getConversion(
            sourceType,
            targetType,
            dateFormat,
            conversionString
        );

        PropertyMapping property = new PropertyMapping(
            parameter.getName(),
            Executables.getPropertyName( sourceAccessor ),
            sourceAccessor.getSimpleName().toString(),
            sourceType,
            Executables.getPropertyName( targetAcessor ),
            targetAcessor.getSimpleName().toString(),
            targetType,
            mappingMethodReference,
            conversion
        );

        if ( !isPropertyMappable( property ) ) {

            // when not mappable, try again with another property mapping method based on parameter only.
            mappingMethodReference = mappingMethodResolver.getMappingMethodReferenceBasedOnParameter(
                method,
                "property '" + Executables.getPropertyName( sourceAccessor ) + "'",
                mapperReferences,
                methods,
                sourceType,
                targetType,
                targetPropertyName,
                dateFormat
            );

            property = new PropertyMapping(
                parameter.getName(),
                Executables.getPropertyName( sourceAccessor ),
                sourceAccessor.getSimpleName().toString(),
                sourceType,
                Executables.getPropertyName( targetAcessor ),
                targetAcessor.getSimpleName().toString(),
                targetType,
                mappingMethodReference,
                conversion
            );
        }

        if ( !isPropertyMappable( property ) ) {
            messager.printMessage(
                Kind.ERROR,
                String.format(
                    "Can't map property \"%s %s\" to \"%s %s\".",
                    property.getSourceType(),
                    property.getSourceName(),
                    property.getTargetType(),
                    property.getTargetName()
                ),
                method.getExecutable()
            );
        }
        return property;
    } 
                            #location 32 
                            #vulnerability type NULL_DEREFERENCE