new

# File activerecord/lib/arel/nodes/update_statement.rb, line 8
      def initialize(relation = nil)
        super()
        @relation = relation
        @wheres   = []
        @values   = []
        @groups   = []
        @havings  = []
        @orders   = []
        @limit    = nil
        @offset   = nil
        @key      = nil
      end