def METHOD_NAME(self, tls_idx):
    """
    Get the start address of a module's TLS data area via the module's TLS
    index.
    From the PE/COFF spec:
        The code uses the TLS index and the TLS array location (multiplying
        the index by the word size and using it as an offset into the
        array) to get the address of the TLS data area for the given
        program and module.
    """
    if 0 <= tls_idx < self.used_modules:
        return self.memory.unpack_word(tls_idx * self.arch.bytes)
    else:
        raise IndexError("TLS index out of range")