IsPartWithinCalloutBox Property
Gets or sets a value indicating whether the text part will be contained within the main callout.
If this is set to true, the main callout will expand to encompass this text part,
and a line will be draw separating the part from the rest of the callout.
This line will have the same symbol as the callout outline and will only draw if
the text part is above or below the top and bottom margins of the middle text.
Target Platforms: Windows 11, Windows 10
ArcGIS Pro version: 3 or higher.