class_docstr: A BcolzDailyBarReader which returns a constant value for spot price.
code: def get_value(self, sid, day, column):
      return 100.0
  
imports: from os.path import dirname, join, realpath
  from nose_parameterized import parameterized
  import numpy
  from numpy import arange, full_like, nan
  import pandas
  from pandas import DataFrame, date_range, Series, Timestamp
  from catalyst.algorithm import TradingAlgorithm
  from catalyst.api import attach_pipeline, pipeline_output, get_datetime
  from catalyst.errors import AttachPipelineAfterInitialize, PipelineOutputDuringInitialize, NoSuchPipeline
  from catalyst.lib.adjustment import MULTIPLY
  from catalyst.pipeline import Pipeline
  from catalyst.pipeline.data import USEquityPricing
  from catalyst.pipeline.loaders.frame import DataFrameLoader
  from catalyst.testing.fixtures import WithDataPortal, CatalystTestCase
  from catalyst.utils.calendars import get_calendar
label_desc: Use image node_id 1 for calling the MockDailyBarSpotReader obj's underlying member method code with example usage: obj.get_value(sid, day, column) and returns: int