private void append(String str) {
            try {
                writer.append(str);
            } catch (IOException ioe) {
                throw new SdkClientException(
                        "Unable to write to the target file to persist the profile credentials.",
                        ioe);
            }
        }
This method handles IOException that occurs when calling the append
method on the writer.
aws-java-sdk-core/src/main/java/com/amazonaws/auth/profile/ProfilesConfigFileWriter.java