TraceKey extension type Graphs
A known key for a scalar value in a trace.
This type is used for known keys in a trace, and is used to push scalar
values, such as heuristic values, to a trace, or allow custom values
using the TraceKey.custom constructor.
- on
 
Constructors
- TraceKey.custom(String key)
 - 
          The key for a custom value.
            const