The importmulti help text reads, in part: 

```
{                                                          (json object) If a ranged descriptor is used, this specifies the start and end of the range to import
           "start": n,                                              (numeric, optional, default=0) Start of the range to import
           "end": n,                                                (numeric, required) End of the range to import (inclusive)
},
```

This is a value for which a key is missing; it should be "range": { ...
{
    std::string ret;
    
    ret += m_name;
    bool was_optional{false};
    for (const auto& arg : m_args) {
        const bool optional = arg.IsOptional();
        ret += " ";
        if (optional) {
            if (!was_optional) ret += "( ";
            was_optional = true;
        } else {
            if (was_optional) ret += ") ";
            was_optional = false;
        }
        ret += arg.ToString( true);
    }
    if (was_optional) ret += " )";
    ret += "\n";
    
    ret += m_description;