getProgramFromShaders(vsCode, fsCode) {
        return this.programs.find((element) => {
            return this.isSameShader(element.vsCode, vsCode) && this.isSameShader(element.fsCode, fsCode);
        });
    }
Returns a program from our cache if this program's vertex and fragment shaders code are the same as the one provided

     params:
     @vsCode (string): vertex shader code
     @fsCode (string): fragment shader code

     returns:
     @program (Program class object or null): our program if it has been found
*