code: public static boolean containsAllContentEqualsIgnoreCase(Collection<CharSequence> a, Collection<CharSequence> b) {
          for (CharSequence v : b) {
              if (!containsContentEqualsIgnoreCase(a, v)) {
                  return false;
              }
          }
          return true;
      }
docs: Determine if {@code a} contains all of the values in {@code b} using
  {@link #contentEqualsIgnoreCase(CharSequence, CharSequence)} to compare values.
  @param a The collection under test.
  @param b The values to test for.
  @return {@code true} if {@code a} contains all of the values in {@code b} using
  {@link #contentEqualsIgnoreCase(CharSequence, CharSequence)} to compare values. {@code false} otherwise.
  @see #contentEqualsIgnoreCase(CharSequence, CharSequence)