code: def upgrade():
      op.create_table(
          "cache_keys",
          sa.Column("id", sa.Integer(), nullable=False),
          sa.Column("cache_key", sa.String(256), nullable=False),
          sa.Column("cache_timeout", sa.Integer(), nullable=True),
          sa.Column("datasource_uid", sa.String(64), nullable=False),
          sa.Column("created_on", sa.DateTime(), nullable=True),
          sa.PrimaryKeyConstraint("id"),
      )
      op.create_index(
          op.f("ix_cache_keys_datasource_uid"),
          "cache_keys",
          ["datasource_uid"],
          unique=False,
      )
  
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