code: func (v *Entry) SetInputPurpose(purpose InputPurpose) {
  	C.gtk_entry_set_input_purpose(v.native(), C.GtkInputPurpose(purpose))
  }
docs: // TODO(jrick) GdkRectangle
  /*
  func (v *Entry) GetIconArea() {
  }
  */
  // SetInputPurpose() is a wrapper around gtk_entry_set_input_purpose().