Arduino: 1.6.7 (Windows 10), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"

In file included from C:\Users\Aurelian\Documents\Arduino\libraries\ITEADLIB_Arduino_SIMCom-master/SIM900.h:5:0,

                 from C:\Users\Aurelian\Documents\Arduino\libraries\ITEADLIB_Arduino_SIMCom-master\examples\GSM_GPRSLibrary_SMS\GSM_GPRSLibrary_SMS.ino:1:

C:\Users\Aurelian\Documents\Arduino\libraries\ITEADLIB_Arduino_SIMCom-master/GSM.h:190:21: error: redeclaration of 'SoftwareSerial GSM::_cell'

      SoftwareSerial _cell;

                     ^

C:\Users\Aurelian\Documents\Arduino\libraries\ITEADLIB_Arduino_SIMCom-master/GSM.h:187:15: note: previous declaration 'HWSerial GSM::_cell'

      HWSerial _cell;

               ^

exit status 1
Error compiling.

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