this unification step succeeds as well.
Unification of the LHS and RHS of the equation is now finished.
Type inference succeeds because there is only one type equation,
no unification step failed, and the map is fully populated.
</p>

<p>
Unification uses a combination of <i>exact</i> and <i>loose</i>
unification depending on whether two types have to be
<a href="#Type_identity">identical</a>,

    *   Fix `while_v2` with variables in custom gradient.
    *   Support taking gradients of V2 `tf.cond` and `tf.while_loop` using
        `LookupTable`.
    *   Fix bug where `vectorized_map` failed on inputs with unknown static
        shape.
    *   Add preliminary support for sparse CSR matrices.
    *   Tensor equality with `None` now behaves as expected.

pkg testing, method (*B) Error(...interface{})
pkg testing, method (*B) Errorf(string, ...interface{})
pkg testing, method (*B) Fail()
pkg testing, method (*B) FailNow()
pkg testing, method (*B) Failed() bool
pkg testing, method (*B) Fatal(...interface{})
pkg testing, method (*B) Fatalf(string, ...interface{})
pkg testing, method (*B) Log(...interface{})
pkg testing, method (*B) Logf(string, ...interface{})

pkg testing, type TB interface, Errorf(string, ...interface{})
pkg testing, type TB interface, Fail()
pkg testing, type TB interface, FailNow()
pkg testing, type TB interface, Failed() bool
pkg testing, type TB interface, Fatal(...interface{})
pkg testing, type TB interface, Fatalf(string, ...interface{})
pkg testing, type TB interface, Log(...interface{})