code: public void attribute(String attribute, String expectedValue) {
          String value = checkAttribute(attribute, expectedValue, 0, 0);
          String reason = NO_ELEMENT_FOUND;
          if (value == null && getElement().is().present()) {
              reason = "Attribute doesn't exist";
          }
          assertNotNull(reason, value);
          assertEquals("Attribute Mismatch", expectedValue, value);
      }
docs: Asserts that the element has an attribute with a value equals to the
  value provided. If the element isn't present, or the element does not
  have the attribute, this will constitute a failure, same as a mismatch.
  This information will be logged and recorded, with a screenshot for
  traceability and added debugging support.
  
  @param attribute     - the attribute to be checked
  @param expectedValue the expected value of the passed attribute of the element