public StatEdge getFirstSuccessor() {
    ValidationHelper.successorsExist(this);
    // TODO: does this make sense here?
//    ValidationHelper.oneSuccessor(this);

    List<StatEdge> res = this.mapSuccEdges.get(STATEDGE_ALL);
    if (res != null) {
      for (StatEdge e : res) {
        return e;
      }
    }

    throw new IllegalStateException("No successor exists for " + this);
  }
Gets the implicitly defined variables in this statement.

@return A list of {@link VarExprent}s that are implicitly defined. Can be null or empty if none exist.
src/org/jetbrains/java/decompiler/modules/decompiler/stats/Statement.java