class IRB::Statement

def evaluable_code 

def evaluable_code
  raise NotImplementedError
end

def is_assignment? 

def is_assignment?
  raise NotImplementedError
end

def should_be_handled_by_debugger? 

def should_be_handled_by_debugger?
  raise NotImplementedError
end

def suppresses_echo? 

def suppresses_echo?
  raise NotImplementedError
end