def import_from_xdr(self, xdr):
        """Create a :class:`TransactionEnvelope
        <stellar_base.transaction_envelope.TransactionEnvelope>` via an XDR
        object.

        In addition, sets the fields of this builder (the transaction envelope,
        transaction, operations, source, etc.) to all of the fields in the
        provided XDR transaction envelope.

        :param xdr: The XDR object representing the transaction envelope to
            which this builder is setting its state to.
        :type xdr: bytes, str

        """
        te = Te.from_xdr(xdr)
        if self.network.upper() in NETWORKS:
            te.network_id = Network(NETWORKS[self.network]).network_id()
        else:
            te.network_id = Network(self.network).network_id()
        self.te = te
        self.tx = te.tx  # with a different source or not .
        self.ops = te.tx.operations
        self.address = te.tx.source
        self.sequence = te.tx.sequence - 1
        time_bounds_in_xdr = te.tx.time_bounds
        if time_bounds_in_xdr:
            self.time_bounds = {
                'maxTime': time_bounds_in_xdr[0].maxTime,
                'minTime': time_bounds_in_xdr[0].minTime
            }
        else:
            self.time_bounds = None
        self.memo = te.tx.memo
        return self
Create a :class:`TransactionEnvelope
        <stellar_base.transaction_envelope.TransactionEnvelope>` via an XDR
        object.

        In addition, sets the fields of this builder (the transaction envelope,
        transaction, operations, source, etc.) to all of the fields in the
        provided XDR transaction envelope.

        :param xdr: The XDR object representing the transaction envelope to
            which this builder is setting its state to.
        :type xdr: bytes, str