code: public void setLabel(String label) {
          this.label.setText(label);
  
          if (!getPlaceholder().isEmpty()) {
              this.label.setStyleName(CssName.ACTIVE);
          }
      }
docs: Set the label of this field.
  <p>
  This will be displayed above the field when values are
  assigned to the box, otherwise the value is displayed
  inside the box.
  </p>