public DozerBeanMapperBuilder withCustomFieldMapper(CustomFieldMapper customFieldMapper) {
        this.customFieldMapper = customFieldMapper;
        return this;
    }
Registers a {@link CustomFieldMapper} for the mapper. Mapper has only one custom field mapper,
and thus consecutive calls of this method will override previously specified value.
<p>
By default, no custom field mapper is registered.

@param customFieldMapper custom field mapper to be registered for the mapper.
@return modified builder to be further configured.
core/src/main/java/com/github/dozermapper/core/DozerBeanMapperBuilder.java