androidx.text.kotlin.CharSequence

isDigitsOnly	`fun CharSequence.isDigitsOnly(): Boolean` Returns whether the given CharSequence contains only digits.
toSpannable	`fun CharSequence.toSpannable(): Spannable` Returns a new Spannable from CharSequence, or the source itself if it is already an instance of SpannableString.
toSpanned	`fun CharSequence.toSpanned(): Spanned` Returns a new Spanned from CharSequence, or the source itself if it is already an instance of SpannedString.
trimmedLength	`fun CharSequence.trimmedLength(): Int` Returns the length that the specified CharSequence would have if spaces and ASCII control characters were trimmed from the start and end, as by String.trim.