code: function formatZSchemaError (errors, indent) {
    indent = indent || "  ";
    var message = "";
    errors.forEach(function (error, index) {
      message += util.format("%s%s at #/%s\n", indent, error.message, error.path.join("/"));
      if (error.inner) {
        message += formatZSchemaError(error.inner, indent + "  ");
      }
    });
    return message;
  }
docs: Z-Schema validation errors are a nested tree structure.
  This function crawls that tree and builds an error message string.
  
  @param {object[]}  errors     - The Z-Schema error details
  @param {string}    [indent]   - The whitespace used to indent the error message
  @returns {string}