    class WillNotRunError(Exception): pass

    class PropertiesObject(UserDict):

        ## Init and reading ##
        def __init__(self, filename=None):
        def readFileNamed(self, filename):

        ## Self utility ##
        def cleanPrivateItems(self):
        def createDerivedItems(self):
        def createVersionString(self):
        def createRequiredPyVersionString(self):
        def createWillRun(self):
        def willRunKeys(self):
        def checkRequiredPyVersion(self):
        def checkRequiredOpSys(self):
        def checkDeniedOpSys(self):
        def checkRequiredSoftware(self):
        def checkWillRunFunc(self):