Indexes the of.

Searches for the specified object and returns the zero-based index of the first occurrence within the range of elements in the List<(Of <(<'T>)>)> that extends from the specified index to the last element.

Searches for the specified object and returns the zero-based index of the first occurrence within the range of elements in the List<(Of <(<'T>)>)> that starts at the specified index and contains the specified number of elements.