old_contents: self.gauge( ... ) # Sample a gauge metric
  
  self.increment( ... ) # Increment a counter metric
  
  self.decrement( ... ) # Decrement a counter metric
  
  self.histogram( ... ) # Sample a histogram metric
  
  self.rate( ... ) # Sample a point, with the rate calcualted at the end of the check
new_contents: self.gauge( ... ) # Sample a gauge metric
  
  self.increment( ... ) # Increment a counter metric
  
  self.decrement( ... ) # Decrement a counter metric
  
  self.histogram( ... ) # Sample a histogram metric
  
  self.rate( ... ) # Sample a point, with the rate calculated at the end of the check
  
subject: fix minor typo in guides-agentchecks-methods.py