C# - Trim() String using a string instead of a single char

Today I found that C# does not have a built in method for trimming strings using another string. The built in method for trimming strings does not take a string, but only a char. However I was in need of trimming the string using a specific sequence of chars. Here is what I have used:

public string Trim(string toBeTrimmed, string trimString){
   if (toBeTrimmed == null || trimString == null)
      return toBeTrimmed;
   while (toBeTrimmed.StartsWith(trimString))
      toBeTrimmed = toBeTrimmed.Substring(trimString.Length);
   return toBeTrimmed;

The above loops over the string and substrings it, until it no longer starts with the given string. The following is how it is invoked:

var trimmedString = Trim("abcabccbaabcTestTest", "abc");
Console.WriteLine("Result:" + trimmedString); 
// Output = Result:cbaabcTestTest

I hope this helps someone out there, let me know below if it did!