== (DataMapper::Associations::Relationship)

    # File lib/dm-core/associations/relationship.rb, line 368
          def ==(other)
            return true  if equal?(other)
            return false if kind_of_inverse?(other)
            other.respond_to?(:cmp_repository?, true) &&
            other.respond_to?(:cmp_model?, true)      &&
            other.respond_to?(:cmp_key?, true)        &&
            other.respond_to?(:query)                 &&
            cmp?(other, :==)
          end