>>> from liblas import guid
  >>> from liblas import header

  >>> g2 = guid.GUID(key=b'8388f1b8-aa1b-4108-bca3-6bc68e7b062e')
  >>> g2
  8388f1b8-aa1b-4108-bca3-6bc68e7b062e

  >>> header = header.Header()
  >>> header.guid = g2
  >>> header.guid
  8388f1b8-aa1b-4108-bca3-6bc68e7b062e
  >>> str(header.project_id.decode())
  '8388f1b8-aa1b-4108-bca3-6bc68e7b062e'

  >>> g3 = guid.GUID(key=b'8388f1b8-aa1b-4108-bca3-6bc68e7b062e')
  >>> g2 == g3
  True

  >>> try:
  ...     import uuid
  ...     g4 = guid.GUID(key=str(uuid.uuid1()).encode())
  ... except ImportError:
  ...    pass