code: function (name, opts) {
              opts = opts || {};
              if (Array.isArray(name)) {
                  return this.__addCompositePrimaryKey(name, opts);
              } else {
                  opts = merge({}, this.db.serialPrimaryKeyOptions, opts);
                  delete opts.type;
                  return this.addColumn(name, "integer", opts);
              }
          }
docs: Add a primary key to the DDL for the table.  See {@link patio.SchemaGenerator#column}
  for the available options.  Like {@link patio.ALterTableGenerator#addForeignKey}, if you specify
  the column name as an array, it just creates a constraint:
  
  @example
  DB.alterTable("albums", function(){
  this.addPrimaryKey("id");
  //=> ADD COLUMN id serial PRIMARY KEY
  this.addPrimaryKey(["artist_id", "name"])
  //=>ADD PRIMARY KEY (artist_id, name)
  });