Import a public key from data in PEM-format
		:param pem_text: text with public key
		:return: None

def import_public_key(self, pem_text):
		""" Import a public key from data in PEM-format
		:param pem_text: text with public key
		:return: None
		"""
		if isinstance(pem_text, str) is True:
			pem_text = pem_text.encode()
		self.__set_public_key(
			serialization.load_pem_public_key(pem_text, backend=default_backend())
		)