def inject_from( dependencies, overwrite = false )
        injected_attributes.each do |attr|
          next unless dependencies.key? attr.name

          if overwrite || !send( "#{ attr.name }?" )
            send( "#{ attr.name }=", dependencies[ attr.name ] )
          end
        end

        dependencies
      end
def inject_from( dependencies, overwrite = false )
        injected_attributes.each do |attr|
          next unless dependencies.key? attr.name

          if overwrite || !send( "#{ attr.name }?" )
            send( "#{ attr.name }=", dependencies[ attr.name ] )
          end
        end

        dependencies
      end
Feed dependencies from a hash into their associated attributes.
 @param [Hash] dependencies hash describing attributes to inject.
 @param [Boolean] overwrite existing attributes with values in in the hash.