<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def as_dict(self):
 """ Returns dict which contains Pourbaix Entry data. Note that the pH, voltage, H2O factors are always calculated when constructing a PourbaixEntry object. """

        d = {"@module": self.__class__.__module__,
             "@class": self.__class__.__name__}
        if isinstance(self.entry, IonEntry):
            d["entry_type"] = "Ion"
        else:
            d["entry_type"] = "Solid"
        d["entry"] = self.entry.as_dict()
        d["concentration"] = self.concentration
        d["entry_id"] = self.entry_id
        return d