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# ArrayAccess interface
 - sfFormField implements the ArrayAccess interface
 - sfFormField implements the ArrayAccess interface
 - sfFormField implements the ArrayAccess interface
 - sfFormField implements the ArrayAccess interface but in read-only mode
 - sfFormField implements the ArrayAccess interface but in read-only mode
 - sfFormField implements the ArrayAccess interface but in read-only mode
# implements Countable
 - sfFormFieldSchema implements the Countable interface
# implements Iterator
 - sfFormFieldSchema implements the Iterator interface
 - sfFormFieldSchema implements the Iterator interface
 - sfFormFieldSchema implements the Iterator interface
# implements Iterator respecting the order of fields
 - sfFormFieldSchema keeps the order
# Looks like everything went fine.