M.map(&:first)

def is_example_row?
  scenario.class == Cucumber::Ast::OutlineTable::ExampleRow
end
...

def is_example_row?
  scenario.class == Cucumber::Ast::OutlineTable::ExampleRow
end
...

def steps
  @steps ||= begin
    if scenario.class == Cucumber::Ast::OutlineTable::ExampleRow
...

Hash["1","a","2","b"]
 => {"1"=>"a", "2"=>"b"} 

...

Hash[*stuff]

def create_something(min_value)
  loop do
    something = SomeClass.generate_random
...

details.map{|x| x[:subtotal]}

class Array
  def compress
    sorted = compact.uniq.sort
...

class Array
  def compress!
    compact!
...

class Array
  def compress!
    compact!
...

class Array
  # does a kind of ZIP compression for integer arrays
  # examples:
...