question: public ComplexFormat ( String imaginaryCharacter , NumberFormat realFormat , NumberFormat imaginaryFormat ) throws MathIllegalArgumentException , NullArgumentException { if ( imaginaryCharacter == null ) { throw new NullArgumentException ( ) ; } if ( imaginaryCharacter . length ( ) == 0 ) { throw new MathIllegalArgumentException ( LocalizedCoreFormats . NO_DATA ) ; } MathUtils . checkNotNull ( imaginaryFormat , LocalizedCoreFormats . IMAGINARY_FORMAT ) ; MathUtils . checkNotNull ( realFormat , LocalizedCoreFormats . REAL_FORMAT ) ; this . imaginaryCharacter = imaginaryCharacter ; this . imaginaryFormat = imaginaryFormat ; this . realFormat = realFormat ; }
target:  Create an instance with a custom imaginary character, a custom number format for the real part, and a custom number format for the imaginary part.