parameters: (self, global_variable_name)
return_statement: return global_variable_name in self.global_variables
docstring: Return 'True' if the given global variable exists.
  
          Examples:
          >>> model.global_variable_exists('timestep')
docstring_summary: Return 'True' if the given global variable exists.
docstring_tokens: Return True if the given global variable exists .
function: def global_variable_exists(self, global_variable_name):
          """
          Return 'True' if the given global variable exists.
  
          Examples:
          >>> model.global_variable_exists('timestep')
  
          """
          return global_variable_name in self.global_variables
function_tokens: def global_variable_exists ( self , global_variable_name ) : return global_variable_name in self . global_variables