@SuppressWarnings("unchecked")
  private void addPositionalArgs(ArgumentListExpression args) {
    List<Expression> expressions = args.getExpressions();

    if (expressions.size() > 0 && expressions.get(0) instanceof MapExpression) {
      boolean isMixed = expressions.size() > 1;
      addNamedArgs((MapExpression) expressions.get(0), isMixed);
      if (isMixed) {
        addPositionalListArgs(expressions.subList(1, expressions.size()), true);
      }
    } else {
      addPositionalListArgs(expressions, false);
    }
  }
If the given statement is a valid interaction definition, returns the rewritten statement.
If the given statement is not an interaction definition, returns null.
If the given statement is an invalid interaction definition, records a compile error
and returns null.
spock-core/src/main/java/org/spockframework/compiler/InteractionRewriter.java