title: IntelliJ does not generate Copy Constructor
body: <p>I try to automatically generate a copy constructor with IntelliJ, but I can not select this due to the box is grey out. How do I automatically generate a copy constructor by IntelliJ?</p>
  
  <p>My Java Class</p>
  
  <pre><code>public class Parameter {
      public double mA;
      public double mB;
      public double mC;
      public double mD;
      public String mPath;
  
      public Parameter(double mA, double mB, double mC, double mD, String mPath) {
          super();
          this.mA = mA;
          this.mB = mB;
          this.mC = mC;
          this.mD = mD;
          this.mPath = mPath;
      }
  
      public Parameter(double mA, double mB, double mC, double mD) {
          this(mA, mB, mC, mD, "");
      }
  
      public double getA() {
          return mA;
      }
      public double getB() {
          return mB;
      }
      public double getC() {
          return mC;
      }
      public double getD() {
          return mD;
      }
      public String getPath(){
          return mPath;
      }
  }
  </code></pre>
  
  <p>The button is grey out.</p>
  
  <p><img src="https://i.stack.imgur.com/coofY.png" alt="enter image description here"></p>