def attributes
      self.class::ATTRIBUTES_NAMES.inject({}) do |attribs, attrib_name|
        value = self.send(attrib_name)
        attribs[attrib_name] = value unless value.nil?
        attribs
      end
    end
def attributes
      self.class::ATTRIBUTES_NAMES.inject({}) do |attribs, attrib_name|
        value = self.send(attrib_name)
        attribs[attrib_name] = value unless value.nil?
        attribs
      end
    end
Return all attributes as a hash
 @return [Hash]