subgraph method
A complete subgraph
.
Implementation
Parser<Subgraph> subgraph() => ((ref0(subgraphToken) & ref0(id).optional()).optional() &
ref1(token, '{') &
ref0(stmtList) &
ref1(token, '}'))
.map((result) => Subgraph(result[0]?[1], result[2]));