This node's children nodes, e.g. the statements of the statement block.
If any of these entities are omitted, so should this entity.
For progress display
This node's "head", e.g. "{" for a statement block.
For diagnostics
Internal hint for --dump output
Don't try removing this entity (children OK)
For dangling dependencies
This node's "tail", e.g. "}" for a statement block.
Used internally
Represents a slice of the original code.