@classmethod
def fromFile(cls, memoryMapping, aFile):
    """
            aFile must be able to read().
        """
    return cls(aFile, memoryMapping.start, memoryMapping.end, memoryMapping
        .permissions, memoryMapping.offset, memoryMapping.major_device,
        memoryMapping.minor_device, memoryMapping.inode, memoryMapping.pathname
        )
