listGroups 
  inline suspend fun IamClient.listGroups(crossinline block: ListGroupsRequest.Builder.() -> Unit): ListGroupsResponse
Lists the IAM groups that have the specified path prefix.
You can paginate the results using the MaxItems and Marker parameters.
Samples
fun main() { 
   //sampleStart 
   // The following command lists the IAM groups in the current account
val resp = iamClient.listGroups() 
   //sampleEnd
}