code: @SuppressWarnings("unchecked") // Checked with instanceof
      public void set(String name, Object obj) throws IOException {
          if (name.equalsIgnoreCase(MAP)) {
              if (!(obj instanceof List)) {
                throw new IOException("Attribute value should be of" +
                                      " type List.");
              }
              maps = (List<CertificatePolicyMap>)obj;
          } else {
            throw new IOException("Attribute name not recognized by " +
                          "CertAttrSet:PolicyMappingsExtension.");
          }
          encodeThis();
      }
docs: Set the attribute value.