public void setLeadingComponent( JComponent leadingComponent ) {
		putClientProperty( TEXT_FIELD_LEADING_COMPONENT, leadingComponent );
	}
Specifies a component that will be placed at the leading edge of the text field.
<p>
The component will be positioned inside and aligned to the visible text field border.
There is no gap between the visible border and the component.
The laid out component size will be the preferred component width
and the inner text field height.
<p>
The component should be not opaque because the text field border is painted
slightly inside the usually visible border in some cases.
E.g. when focused (in some themes) or when an outline color is specified
(see {@link #setOutline(Object)}).

@since 2
flatlaf-extras/src/main/java/com/formdev/flatlaf/extras/components/FlatPasswordField.java