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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 length(cls, namelen):
        # type: (Type[UDFFileIdentifierDescriptor], int) -> int
        '''
        A class method to calculate the size this UDFFileIdentifierDescriptor
        would take up.

        Parameters:
         cls - The class to use (always UDFFileIdentifierDescriptor).
         namelen - The length of the name.
        Returns:
         The length that the UDFFileIdentifierDescriptor would take up.
        '''
        if namelen > 0:
            namelen += 1
        to_add = struct.calcsize(cls.FMT) + namelen
        return to_add + UDFFileIdentifierDescriptor.pad(to_add)