code: @Nonnull
      public BugInstance setProperty(String name, String value) {
          BugProperty prop = lookupProperty(name);
          if (prop != null) {
              prop.setValue(value);
          } else {
              prop = new BugProperty(name, value);
              addProperty(prop);
          }
          return this;
      }
docs: Set value of given property.
  
  @param name
  name of the property to set
  @param value
  the value of the property
  @return this object, so calls can be chained