Statechart Checks : (C1131) Illegal switch structure: non-unique selected entries

(C1131) Illegal switch structure: non-unique selected entries

The switch_c structure contains a case entry that is repeated. Only the first entry will be executed.
Error In:
Correctness
Example:
switch_c (X)
{
case_c 1:
Y=1;
case_c 1:
Y=2;
default:
Y=3;
}
Erroneous Elements:
Actions, states, and transition labels