Why is this an issue?

Declaring multiple variables on one line is difficult to read.

Noncompliant code example

class MyClass {

  private int a, b;

  public void method(){
    int c; int d;
  }
}

Compliant solution

class MyClass {

  private int a;
  private int b;

  public void method(){
    int c;
    int d;
  }
}

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