question: public JCaret ( final int blinkPeriod , final Color caretColor ) { Preconditions . checkArgument ( blinkPeriod >= 0 , "Error: Blink period can't be negative" ) ; Preconditions . checkNotNull ( caretColor , "Error: Caret color can't be null" ) ; m_caretTimer = new Timer ( blinkPeriod , m_listener ) ; m_caretTimer . setRepeats ( true ) ; m_caretTimer . start ( ) ; }
target:  Creates a new caret with a custom blink period and a custom caret color.