.NET custom attributes

Attributes are key-value pairs containing information that determines the properties of an event or transaction. You can create custom attributes using the AddCustomAttribute API.

When adding custom attribute values to transactions, custom events, spans, and errors, the API accepts an object. This describes how these values are processed and how they will appear in APM. In all cases, NULL values are not recorded.

.NET type	How the value will be represented
`byte, Int16, Int32, Int64` `sbyte, UInt16, UInt32, UInt64`	As an integral value
`float, double, decimal`	A decimal-based number
`string`	A string truncated after 255-bytes. Empty strings are supported.
`bool`	True or false
`DateTime`	A string representation following the ISO-8601 format, including time zone information: `2020-02-13T11:31:19.5767650-08:00`
`TimeSpan`	A decimal-based number representing number of seconds.
everything else	The `ToString()` method will be applied. Custom types must have an implementation of `Object.ToString()` or they will throw an exception.