remove non alphanumeric faster

// Original - https://pastebin.com/k63sWFrS

[ThreadStatic]
public static StringBuilder Builder = new StringBuilder();

public static string RemoveNonAlphanumericFaster(string input)
{
    Builder.Clear();

    for (var i = 0; i < input.Length; i++)
    {
        switch (input[i])
        {
            case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'g':
            case 'h': case 'i': case 'j': case 'k': case 'l': case 'm': case 'n':
            case 'o': case 'p': case 'q': case 'r': case 's': case 't': case 'u':
            case 'v': case 'w': case 'x': case 'y': case 'z': case 'A': case 'B':
            case 'C': case 'D': case 'E': case 'F': case 'G': case 'H': case 'I':
            case 'J': case 'K': case 'L': case 'M': case 'N': case 'O': case 'P':
            case 'Q': case 'R': case 'S': case 'T': case 'U': case 'V': case 'W':
            case 'X': case 'Y': case 'Z': case '0': case '1': case '2': case '3':
            case '4': case '5': case '6': case '7': case '8': case '9': case ' ':
                {
                    Builder.Append(input[i]);
                    continue;
                }

            default:
                {
                    continue;
                }
        }
    }

    return Builder.ToString();
}