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/// @startDocuBlock REST_DOCUMENT_DELETE
/// @brief removes a document
///
/// @RESTHEADER{DELETE /_api/document/{document-handle}, Removes a document}
///
/// @RESTURLPARAMETERS
///
/// @RESTURLPARAM{document-handle,string,required}
/// Removes the document identified by *document-handle*.
///
/// @RESTQUERYPARAMETERS
///
/// @RESTQUERYPARAM{waitForSync,boolean,optional}
/// Wait until deletion operation has been synced to disk.
///
/// @RESTQUERYPARAM{returnOld,boolean,optional}
/// Return additionally the complete previous revision of the changed 
/// document under the attribute *old* in the result.
///
/// @RESTHEADERPARAMETERS
///
/// @RESTHEADERPARAM{If-Match,string,optional}
/// You can conditionally remove a document based on a target revision id by
/// using the *if-match* HTTP header.
///
/// @RESTDESCRIPTION
/// The body of the response contains a JSON object with the information
/// about the handle and the revision. The attribute *_id* contains the
/// known *document-handle* of the removed document, *_key* contains the
/// key which uniquely identifies a document in a given collection, and
/// the attribute *_rev* contains the document revision.
///
/// If the *waitForSync* parameter is not specified or set to *false*,
/// then the collection's default *waitForSync* behavior is applied.
/// The *waitForSync* query parameter cannot be used to disable
/// synchronization for collections that have a default *waitForSync*
/// value of *true*.
///
/// If the query parameter *returnOld* is *true*, then
/// the complete previous revision of the document
/// is returned under the *old* attribute in the result.
///
/// @RESTRETURNCODES
///
/// @RESTRETURNCODE{200}
/// is returned if the document was removed successfully and
/// *waitForSync* was *true*.
///
/// @RESTRETURNCODE{202}
/// is returned if the document was removed successfully and
/// *waitForSync* was *false*.
///
/// @RESTRETURNCODE{404}
/// is returned if the collection or the document was not found.
/// The response body contains an error document in this case.
///
/// @RESTRETURNCODE{412}
/// is returned if a "If-Match" header or *rev* is given and the found
/// document has a different version. The response will also contain the found
/// document's current revision in the *_rev* attribute. Additionally, the
/// attributes *_id* and *_key* will be returned.
///
/// @EXAMPLES
///
/// Using document handle:
///
/// @EXAMPLE_ARANGOSH_RUN{RestDocumentHandlerDeleteDocument}
///     var cn = "products";
///     db._drop(cn);
///     db._create(cn, { waitForSync: true });
///     var document = db.products.save({"hello":"world"});
///
///     var url = "/_api/document/" + document._id;
///
///     var response = logCurlRequest('DELETE', url);
///
///     assert(response.code === 200);
///
///     logJsonResponse(response);
///   ~ db._drop(cn);
/// @END_EXAMPLE_ARANGOSH_RUN
///
/// Unknown document handle:
///
/// @EXAMPLE_ARANGOSH_RUN{RestDocumentHandlerDeleteDocumentUnknownHandle}
///     var cn = "products";
///     db._drop(cn);
///     db._create(cn, { waitForSync: true });
///     var document = db.products.save({"hello":"world"});
///     db.products.remove(document._id);
///
///     var url = "/_api/document/" + document._id;
///
///     var response = logCurlRequest('DELETE', url);
///
///     assert(response.code === 404);
///
///     logJsonResponse(response);
///   ~ db._drop(cn);
/// @END_EXAMPLE_ARANGOSH_RUN
///
/// Revision conflict:
///
/// @EXAMPLE_ARANGOSH_RUN{RestDocumentHandlerDeleteDocumentIfMatchOther}
///     var cn = "products";
///     db._drop(cn);
///     db._create(cn);
///
///     var document = db.products.save({"hello":"world"});
///     var document2 = db.products.save({"hello2":"world"});
///     var url = "/_api/document/" + document._id;
///     var headers = {"If-Match":  "\"" + document2._rev + "\""};
///
///     var response = logCurlRequest('DELETE', url, "", headers);
///
///     assert(response.code === 412);
///
///     logJsonResponse(response);
///   ~ db._drop(cn);
/// @END_EXAMPLE_ARANGOSH_RUN
/// @endDocuBlock
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