`initialize': undefined method `[]' for nil:NilClass (NoMethodError)

[spinisetti]

When Graphite doesn't have data or when there is a connection error, rearview throw below error and it triggers an alert.

-:112:in initialize': undefined method[]' for nil:NilClass (NoMethodError)
from -:214:in new' from -:214:inblock in create_timeseries'
from -:214:in map' from -:214:increate_timeseries'
from -:237:in secure_eval' from -:247:in

'