Ported from createTextWriter of the typescript compiler.
createTextWriter
https://github.com/Microsoft/TypeScript/blob/45eaf42006/src/compiler/utilities.ts#L2548
TypeId
self
Returns the argument unchanged.
Span
Instrumented
Calls U::from(self).
U::from(self)
That is, this conversion is whatever the implementation of From<T> for U chooses to do.
From<T> for U
Subscriber
WithDispatch