def to_xml
      builder = Nokogiri::XML::Builder.new do |xml|
        xml.entry('xmlns'           => 'http://www.w3.org/2005/Atom',
                  'xmlns:data'      => 'http://schemas.microsoft.com/ado/2007/08/dataservices',
                  'xmlns:metadata'  => 'http://schemas.microsoft.com/ado/2007/08/dataservices/metadata',
                  'xmlns:georss'    => 'http://www.georss.org/georss',
                  'xmlns:gml'       => 'http://www.opengis.net/gml',
                  'xml:base'        => 'http://services.odata.org/OData/OData.svc/') do
          xml.category(term: "#{namespace}.#{type}",
                       scheme: 'http://schemas.microsoft.com/ado/2007/08/dataservices/scheme')
          xml.author { xml.name }

          xml.content(type: 'application/xml') do
            xml['metadata'].properties do
              properties.keys.each do |name|
                next if name == primary_key
                get_property(name).to_xml(xml)
              end
            end
          end
        end
      end
      builder.to_xml
    end
def to_xml
      builder = Nokogiri::XML::Builder.new do |xml|
        xml.entry('xmlns'           => 'http://www.w3.org/2005/Atom',
                  'xmlns:data'      => 'http://schemas.microsoft.com/ado/2007/08/dataservices',
                  'xmlns:metadata'  => 'http://schemas.microsoft.com/ado/2007/08/dataservices/metadata',
                  'xmlns:georss'    => 'http://www.georss.org/georss',
                  'xmlns:gml'       => 'http://www.opengis.net/gml',
                  'xml:base'        => 'http://services.odata.org/OData/OData.svc/') do
          xml.category(term: "#{namespace}.#{type}",
                       scheme: 'http://schemas.microsoft.com/ado/2007/08/dataservices/scheme')
          xml.author { xml.name }

          xml.content(type: 'application/xml') do
            xml['metadata'].properties do
              properties.keys.each do |name|
                next if name == primary_key
                get_property(name).to_xml(xml)
              end
            end
          end
        end
      end
      builder.to_xml
    end
Converts Entity to its XML representation.
 @return [String]