If x and y are positive real numbers with \frac{1}{x+y}=\frac{1}{x}-\frac{1}{y}, what is the value of \left(\frac{x}{y}+\frac{y}{x}\right)^{2}?
If x and y are positive real numbers with \frac{1}{x+y}=\frac{1}{x}-\frac{1}{y}, what is the value of \left(\frac{x}{y}+\frac{y}{x}\right)^{2}?