default <FK_ENTITY> ENTITY findBy(
        HasFinder<FK_ENTITY, ENTITY> fkField,
        FK_ENTITY fkEntity) {

        return finderBy(fkField).apply(fkEntity);
    }
Retrieves and returns an Entity that matches the given a foreign key
relation (foreign field and entity). For example, if there is an entity
Carrot with a FK to Hare using the column "hare", then
hares.find(Carrot.HARE, carrot) will return the Hare that the Carrot.HARE
field is pointing to.

@param <FK_ENTITY> the type of the foreign entity

@param fkField the foreign key field
@param fkEntity the foreign key entity
@return an Entity (if any) that matches the given a foreign key relation
(foreign field and entity)
runtime-parent/runtime-core/src/main/java/com/speedment/runtime/core/manager/Manager.java