def wf_distribution_values?(vals)
      vals.each do |times, val|
        wf_distribution_count?(times)
        wf_value?(val)
      end
      true
    end
def wf_distribution_values?(vals)
      vals.each do |times, val|
        wf_distribution_count?(times)
        wf_value?(val)
      end
      true
    end
Validate an array of distribution values
 @param vals [Array[Array]] [count, value]
 @return true if valid
 @raise whichever exception is thrown first when validating
   each component of the distribution.