code: def upgrade():
      op.add_column(
          "datasources",
          sa.Column("cache_timeout", sa.Integer(), nullable=True),
      )
      op.add_column(
          "dbs", sa.Column("cache_timeout", sa.Integer(), nullable=True)
      )
      op.add_column(
          "slices",
          sa.Column("cache_timeout", sa.Integer(), nullable=True),
      )
      op.add_column(
          "tables",
          sa.Column("cache_timeout", sa.Integer(), nullable=True),
      )
  
imports: import sqlalchemy
  from alembic import op
label_desc: Use image node_id 1 for calling a global function with example usage: upgrade() without return types