(PECL event >= 1.4.0-beta)
Represents an HTTP request.
EventHttpRequest::CMD_GET
     GET method(command)
EventHttpRequest::CMD_POST
     POST method(command)
EventHttpRequest::CMD_HEAD
     HEAD method(command)
EventHttpRequest::CMD_PUT
     PUT method(command)
EventHttpRequest::CMD_DELETE
     DELETE command(method)
EventHttpRequest::CMD_OPTIONS
     OPTIONS method(command)
EventHttpRequest::CMD_TRACE
     TRACE method(command)
EventHttpRequest::CMD_CONNECT
     CONNECT method(command)
EventHttpRequest::CMD_PATCH
     PATCH method(command)
EventHttpRequest::INPUT_HEADER
     Request input header type.
EventHttpRequest::OUTPUT_HEADER
     Request output header type.