code: public static UsingPath dropNamedPrimaryIndex(String namespace, String keyspace, String customPrimaryName) {
          //N1QL syntax for dropping a primary with a name is actually similar to dropping secondary index
          return new DefaultDropPath().drop(namespace, keyspace, customPrimaryName);
      }
docs: Drop the primary index of the given namespace:keyspace that has a custom name.
  
  @param namespace the namespace prefix (will be escaped).
  @param keyspace the keyspace (bucket, will be escaped).
  @param customPrimaryName the custom name for the primary index (will be escaped).