How do you define minimum password characters in a GUILayout.PasswordField?

Problem:
Can’t define minimum characters in a password using GUILayout.PasswordField

Example:
In the unity documentation, there is no parameter for setting a minimum character limit even though there is a maximum character limit.

passwordToEdit = GUI.PasswordField (Rect (10, 10, 200, 20), passwordToEdit, "*"[0], 25);

Question:
How do you define minimum password characters in a GUILayout.PasswordField?

if(yourString.Length < yourDesiredMinCharCount) {

// do stuff

}