// an active case instance
CmmnCaseInstance caseInstance = caseDefinition.createCaseInstance();
caseInstance.create();
// a case execution associated with Stage X
CmmnActivityExecution stageX = caseInstance.findCaseExecution("X");
stageX.manualStart();
// a case execution associated with Task A
CmmnActivityExecution taskA = caseInstance.findCaseExecution("A");