How to use the capnp-ts/lib/std/schema.capnp.ElementSize function in capnp-ts

ctx: CodeGeneratorFileContext,
  type: s.Type
): string {
  if (!type.isList()) return getJsType(ctx, type, false);

  const elementType = type.getList().getElementType();
  const elementTypeWhich = elementType.which();

  if (elementTypeWhich === s.Type.LIST) {
    return `capnp.PointerList(${getConcreteListType(ctx, elementType)})`;
  } else if (elementTypeWhich === s.Type.STRUCT) {
    const structNode = lookupNode(ctx, elementType.getStruct().getTypeId());

    if (
      structNode.getStruct().getPreferredListEncoding() !==
      s.ElementSize.INLINE_COMPOSITE
    ) {
      throw new Error(E.GEN_FIELD_NON_INLINE_STRUCT_LIST);
    }

    return `capnp.CompositeList(${getJsType(ctx, elementType, false)})`;
  }

  return ConcreteListType[elementTypeWhich];
}