name <code>E</code> as an interface element. This is called
<i>embedding</i> interface <code>E</code> in <code>T</code>
[<a href="#Go_1.14">Go 1.14</a>].
The type set of <code>T</code> is the <i>intersection</i> of the type sets
defined by <code>T</code>'s explicitly declared methods and the type sets
of <code>T</code>’s embedded interfaces.