class ColDescriptionFunction extends Scalar<String, Object> {

    private static final String NAME = "col_description";
    private static final FunctionName FQN = new FunctionName(PgCatalogSchemaInfo.NAME, NAME);

    public static void register(Functions.Builder module) {
        module.add(
            Signature.scalar(
                FQN,
                DataTypes.INTEGER.getTypeSignature(),
                DataTypes.INTEGER.getTypeSignature(),
                DataTypes.STRING.getTypeSignature()
            ),
            ColDescriptionFunction::new
        );
    }

    public ColDescriptionFunction(Signature signature, BoundSignature boundSignature) {
        super(signature, boundSignature);
    }

    @SafeVarargs
    @Override
    public final String evaluate(TransactionContext txnCtx, NodeContext nodeCtx, Input<Object>... args) {<FILL_FUNCTION_BODY>}
}

        // CrateDB doesn't support comments for table columns, so always return null
        return null;
    
<methods>public BoundSignature boundSignature() ,public Scalar<java.lang.String,java.lang.Object> compile(List<io.crate.expression.symbol.Symbol>, java.lang.String, io.crate.role.Roles) ,public transient abstract java.lang.String evaluate(io.crate.metadata.TransactionContext, io.crate.metadata.NodeContext, Input<java.lang.Object>[]) ,public io.crate.expression.symbol.Symbol normalizeSymbol(io.crate.expression.symbol.Function, io.crate.metadata.TransactionContext, io.crate.metadata.NodeContext) ,public io.crate.metadata.functions.Signature signature() <variables>public static final Set<io.crate.metadata.Scalar.Feature> DETERMINISTIC_AND_COMPARISON_REPLACEMENT,public static final Set<io.crate.metadata.Scalar.Feature> DETERMINISTIC_ONLY,public static final Set<io.crate.metadata.Scalar.Feature> NO_FEATURES,protected final non-sealed BoundSignature boundSignature,protected final non-sealed io.crate.metadata.functions.Signature signature