def add_attribute(name, index=nil)
      attr_mapping = CsvMapper::AttributeMap.new(name.to_sym, index, @context)
      self.mapped_attributes << attr_mapping
      attr_mapping
    end
def add_attribute(name, index=nil)
      attr_mapping = CsvMapper::AttributeMap.new(name.to_sym, index, @context)
      self.mapped_attributes << attr_mapping
      attr_mapping
    end
Add a new attribute to this map.  Mostly used internally, but is useful for dynamic map creation.
 returns the newly created CsvMapper::AttributeMap