presto-main/src/main/java/io/prestosql/type/RealOperators.java/RealOperators/castToVarchar
class RealOperators:    @ScalarOperator(CAST)
    @LiteralParameters("x")
    @SqlType("varchar(x)")
    public static Slice castToVarchar(@SqlType(StandardTypes.REAL) long value)
    {
        return utf8Slice(String.valueOf(intBitsToFloat((int) value)));
    }