title: Proguard - Keep all classes and methods names, but obfuscated Fields
body: <p>I trying to keep all classes and methods names, but obfuscated all the fields in my project.</p>
  
  <p>For example, this code:</p>
  
  <pre><code>public class MyClass {
      private int    myInt;
      public String  myString;
  
      void myMethod() {
          // Method code;
      }
  }
  </code></pre>
  
  <p>Should turn into this code</p>
  
  <pre><code>public class MyClass {
      private int    a1;
      public String  a2;
  
      void myMethod() {
          // Obfuscated method code;
      }
  }
  </code></pre>
  
  <p>Note that the class name and method name doesn't get obfuscated, but the field name does.</p>
  
  <p>I'm guessing it is some sort of combination with <code>keepnames</code> and <code>keepclassmembernames</code>, but I'm not sure what is the correct one.</p>