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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_kinds(start=None, end=None):
 """Return all kinds in the specified range, for the current namespace. Args: start: only return kinds >= start if start is not None. end: only return kinds < end if end is not None. Returns: A list of kind names between the (optional) start and end values. """

  q = Kind.query()
  if start is not None and start != '':
    q = q.filter(Kind.key >= Kind.key_for_kind(start))
  if end is not None:
    if end == '':
      return []
    q = q.filter(Kind.key < Kind.key_for_kind(end))

  return [x.kind_name for x in q]