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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_os_type(self, version_text):
 # pylint: disable=no-self-use """Return the OS type information from the device."""

        os_type = None
        if version_text is None:
            return os_type

        match = re.search("(XR|XE|NX-OS)", version_text)
        if match:
            os_type = match.group(1)
        else:
            os_type = 'IOS'

        if os_type == "XR":
            match = re.search("Build Information", version_text)
            if match:
                os_type = "eXR"
            match = re.search("XR Admin Software", version_text)
            if match:
                os_type = "Calvados"
        return os_type