Exception class hierarchy

The ABL exceptions classes are shown hierarchically, in the following example:

java.lang.Exception
   com.progress.common.exception.ProException
      com.progress.open4gl.Open4GLException
         com.progress.open4gl.BusySessionException
         com.progress.open4gl.ConnectException
            com.progress.open4gl.AppServerIOException
            com.progress.open4gl.BadURLException
            com.progress.open4gl.BrokerIOException
            com.progress.open4gl.ConnectAIAException
            com.progress.open4gl.ConnectFailedException
            com.progress.open4gl.ConnectHttpAuthException
            com.progress.open4gl.ConnectHttpsAuthException
            com.progress.open4gl.ConnectProtocolException
            com.progress.open4gl.ConnectProxyAuthException
            com.progress.open4gl.HostUnknownException
            com.progress.open4gl.InvalidNameServerPortException
            com.progress.open4gl.MsgVersionInvalidException
            com.progress.open4gl.NameServerClientPortException
            com.progress.open4gl.NameServerClientPortRangeException
            com.progress.open4gl.NameServerClientPortRetryException
            com.progress.open4gl.NameServerCommunicationsException
            com.progress.open4gl.NameServerInterruptException
            com.progress.open4gl.NameServerMessageFormatException
            com.progress.open4gl.NoSuchAppServiceException
            com.progress.open4gl.UnknownHostnameException
         com.progress.open4gl.OutputSetException
         com.progress.open4gl.ProDataException
         com.progress.open4gl.RunTime4GLException
            com.progress.open4gl.RunTime4GLErrorException
               com.progress.open4gl.RunTime4GLAppErrorException
               com.progress.open4gl.RunTime4GLStopErrorException
            com.progress.open4gl.RunTime4GLQuitException
            com.progress.open4gl.RunTime4GLStopException
               com.progress.open4gl.RunTime4GLStopAfterException
               com.progress.open4gl.RunTime4GLLockConflictException
         com.progress.open4gl.SchemaValidationException
         com.progress.open4gl.SystemErrorException
            com.progress.open4gl.NetworkException
               com.progress.open4gl.NetworkException.RecvDataException
               com.progress.open4gl.NetworkException.SendDataException
   java.sql.SQLException
      com.progress.open4gl.ProSQLException
         com.progress.open4gl.DeletedRowAccessException
         com.progress.open4gl.SDOModificationException