code: public static <R> IntFunction<R> softenIntFunction(final CheckedIntFunction<R> fn) {
          return t -> {
              try {
                  return fn.apply(t);
              } catch (final Throwable e) {
                  throw throwSoftenedException(e);
              }
          };
      }
docs: Soften a CheckedIntFunction that can throw Checked Exceptions to a standard IntFunction that can also throw Checked Exceptions (without declaring them)
  
  e.g.
  
  <pre>
  {@code
  int loaded = ExceptionSoftener.softenFunction(this::load).applyHKT(id);
  
  public int load(int it) throws IOException
  </pre>
  
  @param fn CheckedIntFunction to be converted to a standard IntFunction
  @return IntFunction that can throw checked Exceptions