Add a small clarification on Span.Builder.setNoParent(). (#364)
Add a small clarification on Span.Builder.setNoParent(). (#364)

* Add a small clarification on Span.Builder.setNoParent().

* Add a comment for setParent() too.

open-telemetry/opentelemetry-java,open-telemetry/opentelemetry-java,open-telemetry/opentelemetry-java