code: public void toEndWith(String end) {
  		Arguments.ensureNotNull(end, "end cannot be null");
  		expectNotNull(this.getValue(), "Expected null to end with '%s'", end);
  		expectTrue(this.getValue().endsWith(end), "Expected '%s' to end with '%s'", this.getValue(), end);
  	}
docs: Checks if the stored {@code String} ends with a given sub string.
  <p>This method throws an {@code AssertionError} if
  <ul>
  <li>the stored {@code String} does not end with {@code end}</li>
  <li>the stored {@code String} is {@code null}</li>
  </ul>
  @throws java.lang.IllegalArgumentException if {@code end} is {@code null}.
  @param end the sub string