def replace(other)
      other = coerce(other)
      delete(difference(other)).insert(other.difference(self))
    end
def replace(other)
      other = coerce(other)
      delete(difference(other)).insert(other.difference(self))
    end
Return a relation that represents a replacement of a relation

 Delete the tuples from the relation that are not in the other relation,
 then insert only new tuples.

 @example
   replacement = relation.delete(other)

 @param [Enumerable] other

 @return [Relation::Operation::Insertion]

 @api public