class Protocol::HTTP2::Priority

present if the PRIORITY flag is set.
this stream depends on (see Section 5.3). This field is only
Stream Dependency: A 31-bit stream identifier for the stream that

def self.default(stream_dependency = 0, weight = 16)

All streams are initially assigned a non-exclusive dependency on stream 0x0. Pushed streams (Section 8.2) initially depend on their associated stream. In both cases, streams are assigned a default weight of 16. 
def self.default(stream_dependency = 0, weight = 16)
	self.new(false, stream_dependency, weight)
end

def self.unpack(data) 

def self.unpack(data)
	stream_dependency, weight = data.unpack(FORMAT)
	
	# Weight:  An unsigned 8-bit integer representing a priority weight for the stream (see Section 5.3).  Add one to the value to obtain a weight between 1 and 256.  This field is only present if the PRIORITY flag is set.
	return self.new(stream_dependency & EXCLUSIVE != 0, stream_dependency & ~EXCLUSIVE, weight + 1)
end

def pack 

def pack
	if exclusive
		stream_dependency = self.stream_dependency | EXCLUSIVE
	else
		stream_dependency = self.stream_dependency
	end
	
	return [stream_dependency, self.weight - 1].pack(FORMAT)
end

def weight= value 

def weight= value
	if VALID_WEIGHT.include?(value)
		super
	else
		raise ArgumentError, "Weight #{value} must be between 1-256!"
	end
end