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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 getTypes(cls):
 """ Get sequence of acceptable model types. Iterates through class attributes and separates the user-defined enumerations from the default attributes implicit to Python classes. i.e. this function returns the names of the attributes explicitly defined above. """


    for attrName in dir(cls):
      attrValue = getattr(cls, attrName)
      if (isinstance(attrValue, type)):
        yield attrName