code: func (c *Config) WriteAsQuads(w quad.Writer, o interface{}) (quad.Value, error) {
  	wr := c.newWriter(w)
  	return wr.writeAsQuads(reflect.ValueOf(o))
  }
docs: // WriteAsQuads writes a single value in form of quads into specified quad writer.
  //
  // It returns an identifier of the object in the output sub-graph. If an object has
  // an annotated ID field, it's value will be converted to quad.Value and returned.
  // Otherwise, a new BNode will be generated using GenerateID function.
  //
  // See LoadTo for a list of quads mapping rules.