and!

# File activerecord/lib/active_record/relation/query_methods.rb, line 1123
    def and!(other) # :nodoc:
      incompatible_values = structurally_incompatible_values_for(other)

      unless incompatible_values.empty?
        raise ArgumentError, "Relation passed to #and must be structurally compatible. Incompatible values: #{incompatible_values}"
      end

      self.where_clause |= other.where_clause
      self.having_clause |= other.having_clause
      self.references_values |= other.references_values

      self
    end