code: void writeODataMetadata(String contextURL) throws XMLStreamException {
  
          xmlWriter.writeNamespace(METADATA, nsConfigurationProvider.getOdataMetadataNs());
          xmlWriter.writeNamespace(ODATA_DATA, nsConfigurationProvider.getOdataDataNs());
          xmlWriter.writeDefaultNamespace(ATOM_NS);
          xmlWriter.writeAttribute(nsConfigurationProvider.getOdataMetadataNs(), ODATA_CONTEXT, contextURL);
          xmlWriter.writeAttribute(ODATA_XML_BASE, oDataUri.serviceRoot());
      }
docs: Write the metadata XML attributes of the root element (both {@code <feed>} and {@code <entry>}).
  
  @param contextURL The 'Context URL' to write.
  @throws XMLStreamException If unable to write to stream