getWrapperUniqueName = (counter = 0) => {
  const tag = `scoped-elements-test-wrapper-${counter}`;

  if (customElements.get(tag) !== undefined) {
    return getWrapperUniqueName(counter + 1);
  }

  return tag;
}
Obtains a unique tag name for the test wrapper
@param {number} [counter=0]
@returns {string}