FunctionADFLibrary   "FunctionADF" 
Augmented Dickey-Fuller test (ADF), The ADF test is a statistical method used to assess whether a time series is stationary – meaning its statistical properties (like mean and variance) do not change over time. A time series with a unit root is considered non-stationary and often exhibits non-mean-reverting behavior, which is a key concept in technical analysis.
Reference:
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- rtmath.net
- en.wikipedia.org
 adftest(data, n_lag, conf) 
  : Augmented Dickey-Fuller test for stationarity.
  Parameters:
     data (array) : Data series.
     n_lag (int) : Maximum lag.
     conf (string) : Confidence Probability level used to test for critical value, (`90%`, `95%`, `99%`).
  Returns: `adf`	The test statistic. \
`crit`	Critical value for the test statistic at the 10 % levels. \
`nobs`	Number of observations used for the ADF regression and calculation of the critical values.
