deleteRange 
  Removes characters in the specified range from this string builder and returns this instance.
Since Kotlin
1.4Parameters
startIndex 
the beginning (inclusive) of the range to remove.
endIndex 
the end (exclusive) of the range to remove.
Throws
or IllegalArgumentException when startIndex is out of range of this string builder indices or when startIndex > endIndex.
Removes characters in the specified range from this string builder and returns this instance.
Since Kotlin
1.4Parameters
startIndex 
the beginning (inclusive) of the range to remove.
endIndex 
the end (exclusive) of the range to remove.
Throws
or IllegalArgumentException when startIndex is out of range of this string builder indices or when startIndex > endIndex.