private static List<AssignmentExprent> getAssignmentsOfWithinOneStatement(Statement start, Exprent target) {
    List<AssignmentExprent> exprents = new ArrayList<>();
    findExprents(start, AssignmentExprent.class, assignment -> assignment.getLeft().equals(target), true, (stat, expr) -> exprents.add(expr));
    return exprents;
  }
Recursively searches for assignments of the target that happen within one statement.
This is done as a list because the intended outcomes of the "1 found" (unique) and "2+ found" (non-unique) cases
are different. (But we don't need to have all the assignments within the root stat
because the non-unique case is a failure.)
src/org/jetbrains/java/decompiler/modules/decompiler/SwitchHelper.java