setFloat64 method

void setFloat64 (int byteOffset, double value, [ Endian endian = Endian.big ])

Sets the eight bytes starting at the specified byteOffset in this object to the IEEE 754 double-precision binary floating-point (binary64) representation of the specified value.

Throws RangeError if byteOffset is negative, or byteOffset + 8 is greater than the length of this object.

Implementation 

void setFloat64(int byteOffset, double value, [Endian endian = Endian.big]) =>
    _unsupported();