android/guava/src/com/google/common/escape/CharEscaper.java
@Override
  public String escape(String string) {
    checkNotNull(string); // GWT specific check (do not optimize)
    // Inlineable fast-path loop which hands off to escapeSlow() only if needed
    int length = string.length();
    for (int index = 0; index < length; index++) {
      if (escape(string.charAt(index)) != null) {
        return escapeSlow(string, index);
      }
    }
    return string;
  }
@Override
  public String escape(String string) {
    checkNotNull(string); // GWT specific check (do not optimize)
    // Inlineable fast-path loop which hands off to escapeSlow() only if needed
    int length = string.length();
    for (int index = 0; index < length; index++) {
      if (escape(string.charAt(index)) != null) {
        return escapeSlow(string, index);
      }
    }
    return string;
  }
Returns the escaped form of a given literal string.

@param string the literal string to be escaped
@return the escaped form of {@code string}
@throws NullPointerException if {@code string} is null