Need help ASAP!

/**

* This method returns a substring of the given input string that is enclosed in two

* given characters.

* @param str is a string that contains at least two characters including open and close

* @param open is a character at the beginning of the string that should be returned.

* @param close is a character at the end of the string that should be returned.

* @return returns a string enclosed in two given characters of open and close .

* @pre The given str contains only one open and one close character.

*/

public static String getSubstring(String str, char open, char close) {

//Insert your code here and change the return statement to fit your implementation.

return "";

}

/**

* This method converts a decimal value into its binary representation.

* @param value is a positive integer number

* @return the binary representation of the input.

* @pre the input is a positive integer number.

*/

public static String decimalToBinary(int value) {

//Insert your code here and change the return statement to fit your implementation.

return "";

}