code: @Override
      public StructValidator getSimpleValidator()
      {
          /* Can we create a simple validator? Yes, if the sub-specs are
           * all simple (leaves == element tokens with no arity modifier);
           * this is always true for mixed.
           */
          ContentSpec[] specs = mContentSpecs;
          int len = specs.length;
          int i;
  
          if (mHasMixed) {
              i = len;
          } else {
              i = 0;
              for (; i < len; ++i) {
                  if (!specs[i].isLeaf()) {
                      break;
                  }
              }
          }
  
          if (i == len) { // all leaves, kewl
              PrefixedNameSet keyset = namesetFromSpecs(mNsAware, specs);
              return new Validator(mArity, keyset);
          }
  
          // Nah, need a DFA...
          return null;
      }
docs: /*
  /////////////////////////////////////////////////
  Public API
  /////////////////////////////////////////////////