code: public MemoryPoolMXBean getTenuredMemoryPoolMXBean() {
          for (String name : this.tenuredGen) {
              MemoryPoolMXBean bean = getMemoryPoolMXBean(name);
              if (bean != null) { return bean; }
          }
          
          return null;
      }
docs: Get the {@link MemoryPoolMXBean} associated with the tenured gen in the
  old generation.  This returns the memory pool that either has the
  configured <code>TenuredGen</code> name or one of the known defaults.  If
  the given pool cannot be found, then <code>null</code> is returned.
  
  @return The memory pool for the tenured gen or <code>null</code>
  
  @see #setTenuredMemoryPool(String)
  @see #getMemoryPoolMXBean(String)
  @see #getMemoryPoolMXBeans()
  @see #TENURED_GEN_DEFAULTS