Sets delivery method of either payload or header
		Favors Content-Location header if set

		Args:
			None

		Returns:
			None: sets attributes in self.binary and headers

def _prep_binary_content(self):

		'''
		Sets delivery method of either payload or header
		Favors Content-Location header if set

		Args:
			None

		Returns:
			None: sets attributes in self.binary and headers
		'''

		# nothing present
		if not self.data and not self.location and 'Content-Location' not in self.resource.headers.keys():
			raise Exception('creating/updating NonRDFSource requires content from self.binary.data, self.binary.location, or the Content-Location header')

		elif 'Content-Location' in self.resource.headers.keys():
			logger.debug('Content-Location header found, using')
			self.delivery = 'header'

		# if Content-Location is not set, look for self.data_location then self.data
		elif 'Content-Location' not in self.resource.headers.keys():

			# data_location set, trumps Content self.data
			if self.location:
				# set appropriate header
				self.resource.headers['Content-Location'] = self.location
				self.delivery = 'header'

			# data attribute is plain text, binary, or file-like object
			elif self.data:

				# if file-like object, set flag for api.http_request
				if isinstance(self.data, io.BufferedIOBase):
					logger.debug('detected file-like object')
					self.delivery = 'payload'

				# else, just bytes
				else:
					logger.debug('detected bytes')
					self.delivery = 'payload'