### Question:
DropDownTextField extends JTextField implements GComponent { @Override public void setText(String text) { hideMatchingWindow(); matchingWindow = null; removeUpdateListeners(); super.setText(text); selectAll(); } DropDownTextField(DropDownTextFieldDataModel<T> dataModel);  DropDownTextField(DropDownTextFieldDataModel<T> dataModel, int updateMinDelay); @Override void setText(String text); boolean isMatchingListShowing(); void setConsumeEnterKeyPress(boolean consume); void setIgnoreEnterKeyPress(boolean ignore); void setMatchingWindowHeight(int height); void addDropDownSelectionChoiceListener(DropDownSelectionChoiceListener<T> listener); void addCellEditorListener(CellEditorListener listener); void removeCellEditorListener(CellEditorListener listener); T getSelectedValue(); void setSelectedValue(T value); void closeDropDownWindow();  }### Answer:
@Test public void testSetText() { setText("d"); JWindow matchingWindow = textField.getActiveMatchingWindow(); assertNull( "The completion window has been created before any completion work " + "has began.", matchingWindow); clearText(); typeText("d", true); clearText(); setText("c"); matchingWindow = textField.getActiveMatchingWindow(); assertNull("The completion window has been created before any completion work has started", matchingWindow); }