fails:StringIO#putc when passed [String] overwrites the character at the current position
fails:StringIO#putc when passed [String] only writes the first character from the passed String
fails:StringIO#putc when passed [Object] it writes the passed Integer % 256 to self
fails:StringIO#putc when passed [Object] pads self with \000 when the current position is after the end
fails:StringIO#putc when passed [Object] tries to convert the passed argument to an Integer using #to_int
fails:StringIO#putc when in append mode appends to the end of self
fails:StringIO#putc when self is not writable raises an IOError
