startSpan abstract method
Starts a api.Span.
The api.Span is created with the provided name and as a child of any existing span context found in the passed context.
Implementation
api.Span startSpan(String name,
{api.Context context,
api.SpanKind kind,
List<api.Attribute> attributes,
List<api.SpanLink> links,
Int64 startTime});