class Arel::Nodes::InsertStatement

def eql?(other)
  self.class == other.class &&
    self.relation == other.relation &&
    self.columns == other.columns &&
    self.select == other.select &&
    self.values == other.values
end

def hash
  [@relation, @columns, @values, @select].hash
end

def initialize(relation = nil)
  super()
  @relation = relation
  @columns  = []
  @values   = nil
  @select   = nil
end

def initialize_copy(other)
  super
  @columns = @columns.clone
  @values =  @values.clone if @values
  @select =  @select.clone if @select
end