code: public void add(ELResolver elResolver) {
  
          if (elResolver == null) {
              throw new NullPointerException();
          }
  
          if (size >= elResolvers.length) {
              ELResolver[] newResolvers = new ELResolver[size * 2];
              System.arraycopy(elResolvers, 0, newResolvers, 0, size);
              elResolvers = newResolvers;
          }
  
          elResolvers[size++] = elResolver;
      }
docs: Adds the given resolver to the list of component resolvers.
  
  <p>Resolvers are consulted in the order in which they are added.</p>
  
  @param elResolver The component resolver to add.
  @throws NullPointerException If the provided resolver is
  <code>null</code>.