title: How to convert null string to empty string in retrofit2?
body: <p>Before moving to retrofit2, I was using volley. To set my pojo value, I was using optString and optInt to retrieve value from JSONObject response. This will replace my null string to empty string and I don't need to add null checks for the same. How will do the same with retrofit2.</p>
  
  <p>Example Json:</p>
  
  <pre><code>{
  company_name : null
  }
  </code></pre>
  
  <p>Pojo class</p>
  
  <pre><code>public class company implements Serializable{
  @SerializedName("company_name")
  private String companyName;
  
  public String getCompanyName(){
  return companyName;
  }
  
  public void setCompanyName(String companyName){
  this.companyName = companyName;
  }
  </code></pre>
  
  <p><strong>String companyName = getCompany();
  cause NullPointerException.</strong> </p>
  
  <p>Is there any way to convert every null string to empty string like optString.?</p>