code: def upgrade():
      if isinstance(op.get_bind().dialect, MySQLDialect):
          # If the columns are already MEDIUMTEXT, this is a no-op
          op.execute("ALTER TABLE slices MODIFY params MEDIUMTEXT")
          op.execute(
              "ALTER TABLE slices MODIFY query_context MEDIUMTEXT"
          )
  
imports: from alembic import op
  from sqlalchemy.dialects.mysql.base import MySQLDialect
label_desc: Use image node_id 1 for calling a global function with example usage: upgrade() without return types