def []=(key, value)
      obj = value.is_a?(String) ? value : YAML::dump(value)
      if exists?(key) # column already exists
        data(key).update(value: obj)
      else
        db.insert(key: key.to_s, value: obj)
      end
    end
def []=(key, value)
      obj = value.is_a?(String) ? value : YAML::dump(value)
      if exists?(key) # column already exists
        data(key).update(value: obj)
      else
        db.insert(key: key.to_s, value: obj)
      end
    end
Assigns the <value> to a given <:key>