FormatProviderAttribute
Marks a property or field as a format provider.
A format provider needs to be of a type which implements IFormatProvider and needs to have a getter.
If set to true, this format provider acts as a default format provider
and is used for all IFormattable conversions without an explicit FormatProvider set.
Only one FormatProviderAttribute in a Mapper can be set to true.
public FormatProviderAttribute()