private void ensureAllPositionalArgumentsWereUsed() {
            int unused = 0;
            for (boolean b : positionals) {
                if (!b) {
                    unused++;
                }
            }
            if (unused > 0) {
                throw error(String.format("Found %d unused positional format arguments", unused));
            }
        }
A BlockOperation that repeats a template for each value referenced by the block. Each iteration pushes
a state to the writer that includes key, value, key.first, and key.last context properties. The name
of the context property can be customized in the template.
smithy-utils/src/main/java/software/amazon/smithy/utils/CodeFormatter.java