append_constraints

# File activerecord/lib/active_record/associations/join_dependency/join_association.rb, line 92
          def append_constraints(join, constraints)
            if join.is_a?(Arel::Nodes::StringJoin)
              join_string = Arel::Nodes::And.new(constraints.unshift join.left)
              join.left = join_string
            else
              right = join.right
              right.expr = Arel::Nodes::And.new(constraints.unshift right.expr)
            end
          end