code: public SolutionStackDescription withPermittedFileTypes(String... permittedFileTypes) {
          if (this.permittedFileTypes == null) {
              setPermittedFileTypes(new com.amazonaws.internal.SdkInternalList<String>(permittedFileTypes.length));
          }
          for (String ele : permittedFileTypes) {
              this.permittedFileTypes.add(ele);
          }
          return this;
      }
docs: <p>
  The permitted file types allowed for a solution stack.
  </p>
  <p>
  <b>NOTE:</b> This method appends the values to the existing list (if any). Use
  {@link #setPermittedFileTypes(java.util.Collection)} or {@link #withPermittedFileTypes(java.util.Collection)} if
  you want to override the existing values.
  </p>
  
  @param permittedFileTypes
  The permitted file types allowed for a solution stack.
  @return Returns a reference to this object so that method calls can be chained together.