code: private MemoryMappedPE getMemoryMappedPE() {
          if (!memoryMapped.isPresent()) {
              memoryMapped = Optional.of(MemoryMappedPE.newInstance(data, this));
          }
          return memoryMapped.get();
      }
docs: Creates new instance of MemoryMappedPE or just returns it, if it is
  already there.
  
  @return memory mapped PE