Splits a column into multiple series based on the column's
		unique values. Then visualize theses series in a chart.
		Parameters: column to split, x axis column, y axis column
		Optional: rsum="1D" to resample and sum data an rmean="1D"
		to mean the data

def mline_(self, col, x=None, y=None, rsum=None, rmean=None):
		"""
		Splits a column into multiple series based on the column's
		unique values. Then visualize theses series in a chart.
		Parameters: column to split, x axis column, y axis column
		Optional: rsum="1D" to resample and sum data an rmean="1D"
		to mean the data
		"""
		return self._multiseries(col, x, y, "line", rsum, rmean)