old_contents: import random
  
  class Simulation:
  	def __init__(self, radius, gap, trials):
  		self.radius = radius
  		self.gap = gap
  		self.trials = trials
  
  	def run_trials(self):
  		hits = 0
  		for _ in xrange(self.trials):
  			x = random.uniform(0.0, self.gap)
  			hits += int(self.gap - x < self.radius or x < self.radius)
  		return hits
  
new_contents: import random
  
  class Simulation:
  	def __init__(self, radius, gap, trials):
  		# Store the `radius`, `gap` and `trials` properties on `self` for future reference
  		self.radius = radius  # Radius of the coin
  		self.gap = gap        # Gap between the two lines that the coin might fall on
  		self.trials = trials  # Number of times to test the coin drop
  
  	def run_trials(self):
  		# Number of times the coin touches one of the lines
  		hits = 0
  
  		# Run this loop `trials` number of times
  		for _ in xrange(self.trials):
  			# Generate a random decimal number between 0 and the `gap`,
  			# used to indicate location of the coin after coin drop
  			x = random.uniform(0.0, self.gap)
  
  			# Boolean value indicating whether the coin touched the line
  			hit = self.gap - x < self.radius or x < self.radius
  
  			# Convert `hit` to either `0` or `1`, and increment the number of hits
  			hits += int(hit)
  
  		# Return the number of hits
  		return hits
  
subject: Add docs for `utils/coin.py`