def []=(name, value)
      @column_keys << name
      @attrs[to_key(name)] = value
      define_accessor(name) unless respond_to?(name)
    end
def []=(name, value)
      @column_keys << name
      @attrs[to_key(name)] = value
      define_accessor(name) unless respond_to?(name)
    end
Set the given attribute to value