Values:
MODE_UNSPECIFIED (0):
Mode is unspecified. The view will default to COLOR.
COLOR (1):
The chart distinguishes data series using
different color. Line colors may get reused when
there are many lines in the chart.
X_RAY (2):
The chart uses the Stackdriver x-ray mode, in
which each data set is plotted using the same
semi-transparent color.
STATS (3):
The chart displays statistics such as
average, median, 95th percentile, and more.
