(PECL solr >= 0.9.2)
SolrDocument::__set — Adds another field to the document
$fieldName, string $fieldValue): boolAdds another field to the document. Used to set the fields as new properties.
fieldNameName of the field.
fieldValueField value.
成功時(shí)返回 true， 或者在失敗時(shí)返回 false。