code: public void assertExists(Description description, File actual) {
      assertNotNull(description, actual);
      if (!actual.exists()) {
        String format = "expecting resource in path:<%s> to exist";
        throw failures.failure(description, new BasicErrorMessageFactory(format, actual));
      }
    }
docs: Asserts that the <em>actual</em> {@link File} represents an existing file or directory.
  
  @param description the description of the <em>actual</em> {@code File}.
  @param actual the <em>actual</em> {@code File}.
  @throws AssertionError if the <em>actual</em> {@code File} is {@code null}.
  @throws AssertionError if the <em>actual</em> {@link File} represents a file or directory that does not exist.