AbstractOptionalencoding: _MessageBufferEncodingProtected AbstractallocProtected AbstractasProtected AbstractemptyProtected AbstractfromProtected AbstracttoTries to read the headers from the buffer
OptionallowerCaseKeys: booleanWhether the keys should be stored lower case. Doing so is recommended since HTTP headers are case insensitive.
the header properties or undefined in not enough data can be read.
Append data to the message buffer.