code: def upgrade():
      op.add_column(
          "tables", sa.Column("extra", sa.Text(), nullable=True)
      )
      op.add_column(
          "sql_metrics", sa.Column("extra", sa.Text(), 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