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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 qt_at_least(needed_version, test_version=None):
 """Check if the installed Qt version is greater than the requested :param needed_version: minimally needed Qt version in format like 4.8.4 :type needed_version: str :param test_version: Qt version as returned from Qt.QT_VERSION. As in 0x040100 This is used only for tests :type test_version: int :returns: True if the installed Qt version is greater than the requested :rtype: bool """

    major, minor, patch = needed_version.split('.')
    needed_version = '0x0%s0%s0%s' % (major, minor, patch)
    needed_version = int(needed_version, 0)

    installed_version = Qt.QT_VERSION
    if test_version is not None:
        installed_version = test_version

    if needed_version <= installed_version:
        return True
    else:
        return False