I checkouted this file to previous commit and if run mvn install I got error:
[ERROR] LongCounter.java[24:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[26:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[28:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[29:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[30:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[31:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[33:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[34:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[35:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[36:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[38:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[39:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[40:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[41:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[43:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[44:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[45:n/a] Line has leading space characters; indentation should be performed with tabs only.
[ERROR] LongCounter.java[46:n/a] Line has leading space characters; indentation should be performed with tabs only.