Sensor values mix up when using multiple sensors

When using 2 (or more) sensors on the same device the sensor values read from the sensors can get mixed up.
The struct sense is defined as a global and is reused from multiple instances of the MAX30105 class.

Solution:
Declare sense as class private:

src/MAX30105.h

@@ -140,4 +140,17 @@ class MAX30105 {
   void readRevisionID();
 
   void bitMask(uint8_t reg, uint8_t mask, uint8_t thing);
+
+   #define STORAGE_SIZE 4 //Each long is 4 bytes so limit this to fit on your micro
+  typedef struct Record
+  {
+    uint32_t red[STORAGE_SIZE];
+    uint32_t IR[STORAGE_SIZE];
+    uint32_t green[STORAGE_SIZE];
+    byte head;
+    byte tail;
+  } sense_struct; //This is our circular buffer of readings from the sensor
+
+  sense_struct sense;
+
 };