code: def create_column(self, name, type):
          
          name = normalize_column_name(name)
          if self.has_column(name):
              log.debug("Column exists: %s" % name)
              return
          self._sync_table((Column(name, type),))
docs: Create a new column ``name`` of a specified type.
          ::
  
              table.create_column('created_at', db.types.datetime)
  
          `type` corresponds to an SQLAlchemy type as described by `dataset.db.Types`